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Traditional single-junction binary organic solar cells suffer from narrow absorption windows, limiting their ability to harvest photons. One promising approach to avoid this issue is through the construction of a ternary system to enhance the spectral response and efficiency. However, the complex morphology and photophysical processes within ternary blends leave the criteria of an effective third component unclear, and so they remain a challenge. In this work, we report on the fabrication of PTB7-Th:COi8DFIC-based ternary solar cells with enhanced efficiency by employing either a polymer donor or a nonfullerene acceptor as the third component. We demonstrate that the third component is highly associated with the condensed state of the host acceptor and is the primary factor in determining efficiency improvement. The π-π stacking molecular packing of COi8DFIC helps to maintain the optimal phase separation within the ternary blends and improves both the hole and electron charge mobilities, resulting in enhanced power conversion efficiency of over 14%, compared to 13.1% in binary devices. We also found an excessive amount of polymer donor or nonfullerene acceptor increases the phase separation and encourages lamellar crystallization with the host acceptor domain, resulting in reduced light-harvesting and external quantum efficiencies at long wavelengths. Our results provide a rational guide to selecting the third component to fabricate high-performance nonfullerene-based ternary solar cells. [ABSTRACT FROM AUTHOR]

Vacancy-ordered Cs 2 SnI 6 perovskite as an efficient light harvester sandwiched between the n -ZnO electron transport layer (ETL) and different p-type metal oxides, namely CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO, hole transport layers (HTL) with device architecture of FTO/ZnO/Cs 2 SnI 6 /HTL/Au, a lead-free all inorganic double perovskite solar cells. [Display omitted] • Eco-friendly all inorganic double perovskite solar cells (DPSCs). • Cs 2 SnI 6 double perovskite light harvester and metal oxide charge transport layer. • Ambient stable and highly efficient device with efficiency ∼ 30 %. • Theoretical modelling using SCAPS-1D for high efficiency DPSCs. Non-toxic and air-stable Cesium tin (IV) halide (Cs 2 SnI 6) is a promising alternative to lead halide perovskite for photovoltaic applications. This study reports the extensive analysis of vacancy-ordered Cs 2 SnI 6 perovskite as an efficient light harvester sandwiched between the n -ZnO electron transport layer (ETL) and different p-type metal oxides, namely CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO, hole transport layers (HTL), using SCAPS-1D software. Various physical parameters, viz. thickness, defect density (bulk and interfacial), and charge carrier concentration of different layers for the device architecture of FTO/ZnO/Cs 2 SnI 6 /HTL/Au, are systematically investigated along with the effect of parasitic resistance, work function, and operating temperature in the quest for best device performance in terms of photoconversion efficiency (PCE). The effect of DC biasing voltage is analyzed using C-V characteristics to understand the spatial charge distribution, absorber doping profile, and junction built-in potential. The frequency-dependent admittance was studied using simulated C-f characteristics to give an insight into the defect and the conductance. The Cesium tin (IV) halide (Cs 2 SnI 6) based device optimized with CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO HTLs has shown PCE of 28.18 %, 29.72 %, 29.43 %, and 29.33 %, respectively. [ABSTRACT FROM AUTHOR]

We have introduced a novel approach to enhance the perovskite solar cell efficiency by controlling the grain growth and light harvesting properties of perovskite crystallites. Instead of using a mesoporous TiO 2 layer, we have modified the surface microstructuring of the TiO 2 film by dispensing nano assembled TiO 2 submicron structures (nanobeads, NBs) on TiO 2 compact layer. With this new approach solar cell efficiency was improved significantly through an increase in both J sc and V oc . This high efficiency is attributed to crystallite size of the perovskite phase. These also act as light scattering centers giving higher current density and reduced recombination effects giving higher open circuit voltage. [ABSTRACT FROM AUTHOR]