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With the development of novel semiconductors for optoelectronic applications, new device functionalities utilizing unique characteristics of emerging materials can be particularly appealing. Here, we demonstrate a reversible control of photoluminescence (PL) emission from lead-halide perovskites achieved in perovskite electric-double-layer transistors. PL in several prototypical lead-halide perovskite compounds is shown to be reversibly tuned by a small gate voltage in the range ±1.2 V applied to the ionic-liquid gel on the perovskite surface, with the intensity modulation that can reach one to two orders of magnitude. This effect may be mediated by a reversible migration of oxygen ions affecting the crystal region near the interface with the ion gel. The resulting passivation (or activation) of non-radiative recombination centers (traps) by oxygen ions would then modulate the population of mobile photogenerated electrons and holes that give rise to PL, which is thus tuned with an electric "knob" (the gate) in these devices. [ABSTRACT FROM AUTHOR]

The field of organic electronics is still lacking ubiquitous organic transistors with an efficient electron (n-type) transport that are environmentally and electrically robust. Here, solution-processed n-type N,N′-1H,1H-perfluorobutyldicyanoperylene-carboxydi-imide organic field-effect transistors (OFETs) are reported and it is demonstrated that they are highly stable while operating both in vacuum and in the air at least up to temperatures as high as ≈100 °C. In addition, these crystalline thin-film transistors are found to be resilient to photooxidation under intense illumination in oxygen atmosphere. The performance of these environmentally stable n-type OFETs is on par with the commercial amorphous Si transistors: the highest electron mobility obtained in this study is μmax ≈ 0.6 cm2 V−1 s−1, while the average reproducible mobility is ⟨ μ⟩ = 0.4 cm2 V−1 s−1. Importantly, no parasitic gate voltage VG sweep rate dependence of the nominal mobility in these devices is observed. In addition, the charge carrier mobility has been found to be temperature independent in the range T ≈ 250-373 K. The observed great operational stability and resilience against photooxidation, as well as a temperature-independent mobility in these solution-processed n-type OFETs are beneficial for furthering practical applications of organic semiconductor devices. [ABSTRACT FROM AUTHOR]

Utilizing the intrinsic mobility–strain relationship in semiconductors is critical for enabling strain engineering applications in high‐performance flexible electronics. Here, measurements of Hall effect and Raman spectra of an organic semiconductor as a function of uniaxial mechanical strain are reported. This study reveals a very strong, anisotropic, and reversible modulation of the intrinsic (trap‐free) charge carrier mobility of single‐crystal rubrene transistors with strain, showing that the effective mobility of organic circuits can be enhanced by up to 100% with only 1% of compressive strain. Consistently, Raman spectroscopy reveals a systematic shift of the low‐frequency Raman modes of rubrene to higher (lower) frequencies with compressive (tensile) strain, which is indicative of a reduction (enhancement) of thermal molecular disorder in the crystal with strain. This study lays the foundation of the strain engineering in organic electronics and advances the knowledge of the relationship between the carrier mobility, low‐frequency vibrational modes, strain, and molecular disorder in organic semiconductors. [ABSTRACT FROM AUTHOR]