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Producing heterostructures of cesium lead halide perovskites and metal-chalcogenides in the form of colloidal nanocrystals can improve their optical features and stability, and also govern the recombination of charge carriers. Herein, the synthesis of red-emitting CsPbI3/ZnSe nanoheterostructures is reported via an in situ hot injection method, which provides the crystallization conditions for both components, subsequently leading to heteroepitaxial growth. Steady-state absorption and photoluminescence studies alongside X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy analysis evidence on a type-I band alignment for CsPbI3/ZnSe nanoheterostructures, which exhibit photoluminescence quantum yield of 96% due to the effective passivation of surface defects, and an enhancement in carrier lifetime. Furthermore, the heterostructure growth of ZnSe domains leads to significant improvement in the stability of the CsPbI3 nanocrystals under ambient conditions and against thermal and UV irradiation stress. © 2024 The Author(s). Small published by Wiley-VCH GmbH.

A universal approach to calculating diffusion coefficients in lead halide perovskite single crystals, which have ionic and mixed ionic–electronic conductivity, is proposed. Using impedance spectroscopy, it is demonstrated how to model a non-ideal Warburg element and transmission line equivalent circuit to identify ionic diffusion in the material. The proposed method is applicable to samples of any thickness and electrical properties. Additionally, it is shown how to overcome the challenges of low-frequency impedance measurement and the non-ideal behavior of the elements through extrapolative modeling and approximation.

A universal approach to calculating diffusion coefficients in lead halide perovskite single crystals, which have ionic and mixed ionic–electronic conductivity, is proposed. Using impedance spectroscopy, it is demonstrated how to model a non-ideal Warburg element and transmission line equivalent circuit to identify ionic diffusion in the material. The proposed method is applicable to samples of any thickness and electrical properties. Additionally, it is shown how to overcome the challenges of low-frequency impedance measurement and the non-ideal behavior of the elements through extrapolative modeling and approximation.

A universal approach to calculating diffusion coefficients in lead halide perovskite single crystals, which have ionic and mixed ionic–electronic conductivity, is proposed. Using impedance spectroscopy, it is demonstrated how to model a non-ideal Warburg element and transmission line equivalent circuit to identify ionic diffusion in the material. The proposed method is applicable to samples of any thickness and electrical properties. Additionally, it is shown how to overcome the challenges of low-frequency impedance measurement and the non-ideal behavior of the elements through extrapolative modeling and approximation.

A universal approach to calculating diffusion coefficients in lead halide perovskite single crystals, which have ionic and mixed ionic–electronic conductivity, is proposed. Using impedance spectroscopy, it is demonstrated how to model a non-ideal Warburg element and transmission line equivalent circuit to identify ionic diffusion in the material. The proposed method is applicable to samples of any thickness and electrical properties. Additionally, it is shown how to overcome the challenges of low-frequency impedance measurement and the non-ideal behavior of the elements through extrapolative modeling and approximation.

A heterojunction is the key junction for charge extraction in many thin film solar cell technologies. However, the structure and band alignment of the heterojunction in the operating device are often difficult to predict from calculations and, due to the complexity and narrow thickness of the interface, are difficult to measure directly. In this study, we demonstrate a technique for direct measurement of the band alignment and interfacial electric field variations of a fully functional lead halide perovskite solar cell structure under operating conditions using hard X-ray photoelectron spectroscopy (HAXPES). We describe the design considerations required in both the solar cell devices and the measurement setup and show results for the perovskite, hole transport, and gold layers at the back contact of the solar cell. For the investigated design, the HAXPES measurements suggest that 70% of the photovoltage was generated at this back contact, distributed rather equally between the hole transport material/gold interface and the perovskite/hole transport material interface. In addition, we were also able to reconstruct the band alignment at the back contact at equilibrium in the dark and at open circuit under illumination., QC 20230412

We investigated the influence of two passivating moleculescontaininga P=O group on the performance of quasi-2D Dion-Jacobsonhalide perovskite light-emitting diodes, namely, triphenylphosphineoxide (TPPO) and diphenyl-4-triphenylsilylphenyl phosphine oxide (TSPO1).We found that both passivating molecules lead to increased efficiencycompared to control devices, while they had opposite effects on devicelifetime, with a decrease observed for TPPO and an increase observedfor TSPO1. The two passivating molecules resulted in differences inenergy-level alignment, electron injection, film morphology and crystallinity,and ion migration during operation. While TPPO resulted in mproved photoluminescence decay times, overall higher maximum external quantumefficiency (EQE) and device lifetime were obtained for TSPO1 comparedto TPPO (14.4% vs 12.4% EQE, 341 min vs 42 min T-50).

Harnessing hot-charge relaxation in lead halide perovskites (LHPs) is the key to developing next-generation high-performance concentrator solar cells that break the Shockley-Queisser limit. Though the physical origins of the slow hot-carrier cooling and their interplays have been unveiled, consensus is still lacking concerning the mechanisms of many-body interactions during hot-charge relaxation. Here, we propose a unified theory to explain the spectral and temporal evolution of the band edge in LHPs at the early time-scale following femtosecond laser excitation. We demonstrate that at early times, the hot-biexciton effect imposes a transient bandgap shrinkage decaying rapidly with exciton dissociation. Subsequently, bandgap renormalization (BGR) effect dominates the bandgap change, with a partial compensation by the free-carrier Stark (FCS) effect. Additionally, we confirmed that the shift in the photo-bleaching (PB) peak in the transient absorption (TA) spectra is modulated by carrier temperature rather than the bandgap change, which has negligible influence on the bleaching position, contrary to previous studies. Importantly, this work demonstrates the significant role played by the hot-biexciton interaction to the exciton generation-dissociation and carrier relaxation dynamics in perovskite solar cell materials at early times. Our insights resolve the existing contradictions on the nature of early-time photo-induced absorption and PB shift via reliable quantifications. By unraveling the role of hot-charge cooling and the intricate many-body interactions among the hotbiexciton interplay, BGR and FCS effects, our study contributes to a deeper comprehension of the fundamental photo-physics in LHPs.

Lead halide perovskites (LHP) are rapidly emerging as efficient, low-cost, solution-processable scintillators for radiation detection. Carrier trapping is arguably the most critical limitation to the scintillation performance. Nonetheless, no clear picture of the trapping and detrapping mechanisms to/from shallow and deep trap states involved in the scintillation process has been reported to date, as well as on the role of the material dimensionality. Here, this issue is addressed by performing, for the first time, a comprehensive study using radioluminescence and photoluminescence measurements side-by-side to thermally-stimulated luminescence (TSL) and afterglow experiments on CsPbBr3 with increasing dimensionality, namely nanocubes, nanowires, nanosheets, and bulk crystals. All systems are found to be affected by shallow defects resulting in delayed intragap emission following detrapping via a-thermal tunneling. TSL further reveals the existence of additional temperature-activated detrapping pathways from deeper trap states, whose effect grows with the material dimensionality, becoming the dominant process in bulk crystals. These results highlight that, compared to massive solids where the suppression of both deep and shallow defects is critical, low dimensional nanostructures are more promising active materials for LHP scintillators, provided that their integration in functional devices meets efficient surface engineering.

[EN] This paper explores the gas sensing properties of graphene nanolayers decorated with lead halide perovskite (CH3NH3PbBr3) nanocrystals to detect toxic gases such as ammonia (NH3) and nitrogen dioxide (NO2). A chemical-sensitive semiconductor film based on graphene has been achieved, being decorated with CH3NH3PbBr3 perovskite (MAPbBr3) nanocrystals (NCs) synthesized, and characterized by several techniques, such as field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Reversible responses were obtained towards NO2 and NH3 at room temperature, demonstrating an enhanced sensitivity when the graphene is decorated by MAPbBr3 NCs. Furthermore, the effect of ambient moisture was extensively studied, showing that the use of perovskite NCs in gas sensors can become a promising alternative to other gas sensitive materials, due to the protective character of graphene, resulting from its high hydrophobicity. Besides, a gas sensing mechanism is proposed to understand the effects of MAPbBr3 sensing properties

Colloidal cesium lead halide perovskite nanocrystals exhibit unique photophysical properties including high quantum yields, tunable emission colors, and narrow photoluminescence spectra that have marked them as promising light emitters for applications in diverse photonic devices. Randomly oriented transition dipole moments have limited the light outcoupling efficiency of all isotropic light sources, including perovskites. In this report we design and synthesize deep blue emitting, quantum confined, perovskite nanoplates and analyze their optical properties by combining angular emission measurements with back focal plane imaging and correlating the results with physical characterization. By reducing the dimensions of the nanocrystals and depositing them face down onto a substrate by spin coating, we orient the average transition dipole moment of films into the plane of the substrate and improve the emission properties for light emitting applications. We then exploit the sensitivity of the perovskite electronic transitions to the dielectric environment at the interface between the crystal and their surroundings to reduce the angle between the average transition dipole moment and the surface to only 14° and maximize potential light emission efficiency. This tunability of the electronic transition that governs light emission in perovskites is unique and, coupled with their excellent photophysical properties, introduces a valuable method to extend the efficiencies and applications of perovskite based photonic devices beyond those based on current materials.

Solar hydrogen conversion represents a clean and economic approach to addressing global energy and environmental issues, for which efficient photocatalysts are heavily pursued. Lead halide perovskites are promising candidates for efficient phtocatalysts in solar hydrogen generation due to their attractive properties in light absorption, photogenerated charge transportation, and utilization. However, photocatalytic applications of lead halide perovskites are limited owing to their poor stability in the presence of water or other polar solvent environment. This work presents the rational control of surface ligands in achieving a good balance between stability and photocatalytic activity of CsPbBr3 quantum dots (QDs). Detailed studies reveal that the deliberate surface ligands engineering is crucial for maximizing the photocatalytic activity of CsPbBr3 QDs while maintaining good QD stability. A certain amount of surface ligands protect the CsPbBr3 QDs from decomposition in moisture during the photocatalytic reaction while still enabling efficient charge transfer for photocatalytic reactions on the surface of QDs. The well-controlled CsPbBr3 photocatalyst shows efficient visible light-driven H2 generation with outstanding stability (≥160 h).

This paper explores the gas sensing properties of graphene nanolayers decorated with lead halide perovskite (CH3NH3PbBr3) nanocrystals to detect toxic gases such as ammonia (NH3) and nitrogen dioxide (NO2). A chemical-sensitive semiconductor film based on graphene has been achieved, being decorated with CH3NH3PbBr3 perovskite (MAPbBr3) nanocrystals (NCs) synthesized, and characterized by several techniques, such as field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Reversible responses were obtained towards NO2 and NH3 at room temperature, demonstrating an enhanced sensitivity when the graphene is decorated by MAPbBr3 NCs. Furthermore, the effect of ambient moisture was extensively studied, showing that the use of perovskite NCs in gas sensors can become a promising alternative to other gas sensitive materials, due to the protective character of graphene, resulting from its high hydrophobicity. Besides, a gas sensing mechanism is proposed to understand the effects of MAPbBr3 sensing properties.

Despite years of intense study, even today there are many novel semiconductor materials whose unique properties raise fundamental scientific questions about the relationship between structure and function. Two examples are organic semiconductors and semiconducting nanostructures. Organic semiconductors can be solution processed at room temperature, leading to thin films that are flexible, inexpensive, and more sustainable when compared to inorganic alternatives. Yet solution processing leads to complex microstructures, and the resulting polymorphism, interfaces, and defects all affect the material's behavior in complex ways. In semiconducting nanostructures, the novel behavior arises due to their nanometer-scale dimensions. Confinement and enhanced surface interactions affect the electronic structure and dynamics in sometimes unexpected ways and can produce new physics.Chapters 1 and 2 provide the necessary background for this dissertation. Chapter 1 provides an overview of semiconductors and what makes organic semiconductors distinct. The dynamic processes that are relevant for subsequent chapters are introduced. Chapter 2 describes a home-built transient absorption (TA) microscope that was used in each project discussed here. TA is an important tool for studying a material's ultrafast excited state dynamics, and by combining TA with microscopy we have been able to investigate how those dynamics depend on the local morphology.Chapters 3 and 4 discuss the use of TA microscopy to probe the ultrafast electronic dynamics of individual crystalline domains of organic semiconductors. In Chapter 3 we find that different domains of the material diF-TES-ADT can display different dynamics. We fit a kinetic model to the observed behaviors, quantify the amount of heterogeneity, and propose that the observations are due to polymorphism. In Chapter 4 we study singlet fission in single crystalline domains of the material TIPS-Pentacene. During singlet fission, a singlet exciton sp

A major obstacle and persisting challenge towards safe and sustainable industrial scale processing and commercialization of perovskite based (opto)electronic devices including solar cells lies in the essential need of strongly coordinating toxic solvents such as N, N-dimethylformamide (DMF) in the preparation of perovskite precursor inks. In this work, we present novel ink systems for perovskite precursors composed of protic ionic liquids (PILs) based on methylammonium cation and carboxylate anion and their binary blends with water, alcohols and acetonitrile for solution processing of CH3NH3PbX3 (X = I, Br). Among the investigated ink-systems, new PIL methylammonium propionate and its blends were identified as the most promising candidates in terms of chemical stability and compatibility for single- and two-step solution processing of the perovskite materials. Multi-cation mixed halide perovskites solar cells prepared with PIL/acetonitrile solvent system showed power conversion efficiency in excess of 15%.

Metal halide perovskites have emerged as materials of high interest for solar energy-to-electricity conversion, and in particular, the use of mixed-ion structures has led to high power conversion efficiencies and improved stability. For this reason, it is important to develop means to obtain atomic level understanding of the photoinduced behavior of these materials including processes such as photoinduced phase separation and ion migration. In this paper, we implement a new methodology combining visible laser illumination of a mixed-ion perovskite ((FAP-bI(3))(0.85)(MAPbBr(3))(0.15)) with the element specificity and chemical sensitivity of core-level photoelectron spectroscopy. By carrying out measurements at a synchrotron beamline optimized for low X-ray fluxes, we are able to avoid sample changes due to X-ray illumination and are therefore able to monitor what sample changes are induced by visible illumination only. We find that laser illumination causes partially reversible chemistry in the surface region, including enrichment of bromide at the surface, which could be related to a phase separation into bromide- and iodide-rich phases. We also observe a partially reversible formation of metallic lead in the perovskite structure. These processes occur on the time scale of minutes during illumination. The presented methodology has a large potential for understanding light-induced chemistry in photoactive materials and could specifically be extended to systematically study the impact of morphology and composition on the photostability of metal halide perovskites.

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, we present a protocol for the fabrication of this material via the low-pressure vapor assisted solution process (LP-VASP) method, which yields ~19% power conversion efficiency in planar heterojunction perovskite solar cells. First, we report the synthesis of methylammonium iodide (CH3NH3I) and methylammonium bromide (CH3NH3Br) from methylamine and the corresponding halide acid (HI or HBr). Then, we describe the fabrication of pinhole-free, continuous methylammonium-lead halide perovskite (CH3NH3PbX3 with X = I, Br, Cl and their mixture) films with the LP-VASP. This process is based on two steps: i) spin-coating of a homogenous layer of lead halide precursor onto a substrate, and ii) conversion of this layer to CH3NH3PbI3-xBrx by exposing the substrate to vapors of a mixture of CH3NH3I and CH3NH3Br at reduced pressure and 120 °C. Through slow diffusion of the methylammonium halide vapor into the lead halide precursor, we achieve slow and controlled growth of a continuous, pinhole-free perovskite film. The LP-VASP allows synthetic access to the full halide composition space in CH3NH3PbI3-xBrx with 0 ≤ x ≤ 3. Depending on the composition of the vapor phase, the bandgap can be tuned between 1.6 eV ≤ Eg ≤ 2.3 eV. In addition, by varying the composition of the halide precursor and of the vapor phase, we can also obtain CH3NH3PbI3-xClx. Films obtained from the LP-VASP are reproducible, phase pure as confirmed by X-ray diffraction measurements, and show high photoluminescence quantum yield. The process does not require the use of a glovebox.

Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti., This thesis explores the use of near-field (NF) excited photoluminescent (PL) mapping to investigate optoelectronic properties at the nanometer scale. By overcoming the limitations of traditional far-field optical techniques, it investigates phenomena on smaller length scales that would be previously inaccessible. The primary focus is on NF scanning optical microscopy, enabling the observation of subdiffraction phenomena for studied samples. A notable accomplishment of this thesis is the introduction of NF time-resolved PL mapping, a groundbreaking method for studying dynamic processes beyond the diffraction limit. Importantly, this approach represents a novel contribution to the field, as supported by the literature review presented in this thesis. Through meticulous evaluation and interpretation of PL measurements, this study enhances our understanding of the optical properties of lead halide perovskite materials and their potential applications, e.g. in solar cells. Moreover, it uncovers unexplored opportunities in NF time-resolved PL mapping, providing unprecedented insights into dynamic processes at the subdiffraction limit. By pushing the boundaries of nanoscale optical investigations, this diploma thesis establishes a foundation for new research directions and advancements in the field.

Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti., This thesis explores the use of near-field (NF) excited photoluminescent (PL) mapping to investigate optoelectronic properties at the nanometer scale. By overcoming the limitations of traditional far-field optical techniques, it investigates phenomena on smaller length scales that would be previously inaccessible. The primary focus is on NF scanning optical microscopy, enabling the observation of subdiffraction phenomena for studied samples. A notable accomplishment of this thesis is the introduction of NF time-resolved PL mapping, a groundbreaking method for studying dynamic processes beyond the diffraction limit. Importantly, this approach represents a novel contribution to the field, as supported by the literature review presented in this thesis. Through meticulous evaluation and interpretation of PL measurements, this study enhances our understanding of the optical properties of lead halide perovskite materials and their potential applications, e.g. in solar cells. Moreover, it uncovers unexplored opportunities in NF time-resolved PL mapping, providing unprecedented insights into dynamic processes at the subdiffraction limit. By pushing the boundaries of nanoscale optical investigations, this diploma thesis establishes a foundation for new research directions and advancements in the field.

Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti., This thesis explores the use of near-field (NF) excited photoluminescent (PL) mapping to investigate optoelectronic properties at the nanometer scale. By overcoming the limitations of traditional far-field optical techniques, it investigates phenomena on smaller length scales that would be previously inaccessible. The primary focus is on NF scanning optical microscopy, enabling the observation of subdiffraction phenomena for studied samples. A notable accomplishment of this thesis is the introduction of NF time-resolved PL mapping, a groundbreaking method for studying dynamic processes beyond the diffraction limit. Importantly, this approach represents a novel contribution to the field, as supported by the literature review presented in this thesis. Through meticulous evaluation and interpretation of PL measurements, this study enhances our understanding of the optical properties of lead halide perovskite materials and their potential applications, e.g. in solar cells. Moreover, it uncovers unexplored opportunities in NF time-resolved PL mapping, providing unprecedented insights into dynamic processes at the subdiffraction limit. By pushing the boundaries of nanoscale optical investigations, this diploma thesis establishes a foundation for new research directions and advancements in the field.

Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti., This thesis explores the use of near-field (NF) excited photoluminescent (PL) mapping to investigate optoelectronic properties at the nanometer scale. By overcoming the limitations of traditional far-field optical techniques, it investigates phenomena on smaller length scales that would be previously inaccessible. The primary focus is on NF scanning optical microscopy, enabling the observation of subdiffraction phenomena for studied samples. A notable accomplishment of this thesis is the introduction of NF time-resolved PL mapping, a groundbreaking method for studying dynamic processes beyond the diffraction limit. Importantly, this approach represents a novel contribution to the field, as supported by the literature review presented in this thesis. Through meticulous evaluation and interpretation of PL measurements, this study enhances our understanding of the optical properties of lead halide perovskite materials and their potential applications, e.g. in solar cells. Moreover, it uncovers unexplored opportunities in NF time-resolved PL mapping, providing unprecedented insights into dynamic processes at the subdiffraction limit. By pushing the boundaries of nanoscale optical investigations, this diploma thesis establishes a foundation for new research directions and advancements in the field.

Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti., This thesis explores the use of near-field (NF) excited photoluminescent (PL) mapping to investigate optoelectronic properties at the nanometer scale. By overcoming the limitations of traditional far-field optical techniques, it investigates phenomena on smaller length scales that would be previously inaccessible. The primary focus is on NF scanning optical microscopy, enabling the observation of subdiffraction phenomena for studied samples. A notable accomplishment of this thesis is the introduction of NF time-resolved PL mapping, a groundbreaking method for studying dynamic processes beyond the diffraction limit. Importantly, this approach represents a novel contribution to the field, as supported by the literature review presented in this thesis. Through meticulous evaluation and interpretation of PL measurements, this study enhances our understanding of the optical properties of lead halide perovskite materials and their potential applications, e.g. in solar cells. Moreover, it uncovers unexplored opportunities in NF time-resolved PL mapping, providing unprecedented insights into dynamic processes at the subdiffraction limit. By pushing the boundaries of nanoscale optical investigations, this diploma thesis establishes a foundation for new research directions and advancements in the field.