2D/3D Perovskite Photodetectors with High Response Frequency and Improved Stability Based on Thiophene-2-ethylamine and Dual Additives

Organic-inorganiclead halide perovskite materialshavereceived great attention in recent years. However, the poor stabilityof these materials severely limits the commercial application of perovskitedevices. Here, we used thiophene-2-ethylammonium iodide (TEAI) materialas the organic spacer NH4SCN and NH4Cl as thedual additives to realize high-stability two-dimensional (2D)/three-dimensional(3D) perovskite thin films for perovskite photodetectors. Then, weinvestigated different effects of the dual additives on the orientationand crystallinity of the perovskite films. At room temperature, theoptimized 2D/3D perovskite photodetectors exhibit good performancewith high external quantum efficiency (EQE) (72%), large responsivity(0.36 A/W), high detectivity (2.46 x 10(12) Jones atthe bias of 0 V), high response frequency (1.7 MHz), and improvedstability (retains 90% photocurrent after 2000 h storage in RT and10% RH conditions). Based on these devices, a dual-channel opticaltransport system and a light-intensity adder are achieved. The resultsof this study indicate that, with a simple process, the TEAI and dual-additivesbased 2D/3D perovskite photodetectors have promising applicationsin light-intensity adder and optical communication systems.