De Novo Studies of Working Mechanisms for Self-Driven Narrowband Perovskite Photodetectors

Abstract

Self-driven narrowband perovskite photodetectors have recently attracted significant attention due to their simple preparation, high performance, and amenability for system integration. However, the origin of narrowband photoresponse and the related regulation mechanisms still remains elusive. To address these issues, we herein perform a systematic investigation by formulating an analytic model in conjunction with finite element simulation. The optical and electrical simulations have resulted in design principles for perovskite narrowband photodetectors in terms of the dependence of external quantum efficiency (EQE) on perovskite layer thickness, doping concentration, and band gap as well as trap state concentration. Careful investigations on the profiles of electric field, current, and optical absorption reveal the dependence of narrowband EQE on the direction of incident light and perovskite doping types: only p-type perovskite can yield the narrowband photoresponse for illumination from the hole transport layer (HTL) side. The simulation results demonstrated in this study shed new light on the mechanism of perovskite-based narrowband photodetectors and provide valuable guidance for their design.

Aluminum Carboxylate Modification Enabled Efficient and Stable Perovskite-Polystyrene Thin Films for Light-Emitting Applications

“…Lead halide perovskite nanocrystals (PNCs) possess remarkable optical properties, such as high photoluminescence quantum yield (PLQY), large absorption coefficient, wide range bandgap tunability, and narrow emission line width. − These characteristics make PNCs a promising material for optoelectronic applications, such as light-emitting diodes (LEDs), − solar cells, , and photodetectors. , However, the ionic nature renders PNCs susceptible to light, heat, water, and polar solvents. − Recent studies have shown that the rapid degradation of PNCs is primarily caused by the instability of their surface capping. − The bonding between surface halides and ammonium ligands, facilitated by hydrogen bonds, exhibits high dynamics and can lead to the detachment of the ammonium-halide ion pair during purification and upon exposure to air and light, , resulting in the formation of surface defects and increase of nonradiative recombination …”

“…1−6 These characteristics make PNCs a promising material for optoelectronic applications, such as light-emitting diodes (LEDs), 7−9 solar cells, 10,11 and photodetectors. 12,13 However, the ionic nature renders PNCs susceptible to light, heat, water, and polar solvents. 14−16 Recent studies have shown that the rapid degradation of PNCs is primarily caused by the instability of their surface capping.…”

A sensitive self-powered perovskite photodetector via noise suppression with poly(vinylidene fluoride–trifluoroethylene) doping for defect passivation

“…Organic-inorganic hybrid perovskites have attracted widespread attention in applications of solar cells, light-emitting diodes, and photodetectors, due to their excellent optoelectronic properties. [1][2][3][4][5][6][7][8][9] Especially in the field of photodetection, selfpowered perovskite photodetectors (PDs) play an important role in healthcare, bioimaging and other fields. 10,11 Among them, lead halide perovskite materials show high photocurrent and good stability, and have been widely studied in the field of photodetection.…”

Ion Migration as a New Paradigm to Boost Self‐Driven Perovskite Narrowband Photodetectors

“…[7,8] Because of the simplicity of the system and tunable spectral responses, CCN-type NPDs hold the potential for developing novel optoelectronic devices. [9][10][11][12][13] However, the performances of CCN-type NPDs, such as EQE and SRR, depend on the active layer thickness and external bias, [14,15] and improving the figures-of-merit of such NPDs remains a great challenge.…”