Self-Powered and Broadband Lead-Free Inorganic Perovskite Photodetector with High Stability

Abstract

Metal halide perovskite materials have opened up a great opportunity for high-performance optoelectronic devices owing to their extraordinary optoelectronic properties. More than lead halide ones, stable and nontoxic bismuth halide perovskites exhibit more promise in their future commercialization. In this work, we developed for the first time photodetectors based on full-inorganic Cs 3 Bi 2 I 9−x Br x perovskites and modulate their performance by varying x in the composition systematically. Among those self-powered photodetectors, those based on Cs 3 Bi 2 I 6 Br 3 shows the best performance with excellent photosensitivity of 4.1 × 10 4 at zero bias as well as the responsivity and detectivity reaching 15 mA/W and 4.6 × 10 11 Jones, respectively. More strikingly, the full-inorganic perovskite photodetectors exhibit excellent stability in the ambient environment and can maintain over 96% of the initial value after 100 days owing to the high stability of the core perovskite film. The paper definitely paves an alternative and promising strategy for the design of future commercial photodetectors that are self-powered, stable, nontoxic, etc.

Engineering Chemical Vapor Deposition for Lead‐Free Perovskite‐Inspired MA3Bi2I9 Self‐Powered Photodetectors with High Performance and Stability

“…[ 47 ] Therefore, our photodetectors featuring MBI films grown through 2T‐CVD surpass the environmental stability of all other bismuth‐based PIM photodetectors reported in the literature (Table 1). [ 46–50 ] The cutting‐edge stability of 2T‐CVD photodetectors may be traced to the uniform, compact and smooth films produced with the 2T‐CVD approach, consistent with our previous findings from lead‐halide perovskite devices. [ 23,24,33,56–61 ] In fact, grain boundaries in polycrystalline films have often been linked to the degradation of perovskite/perovskite‐inspired materials in a humid environment.…”

“…[ 46 ] Additionally, all devices based on inorganic double perovskites have similar responsivity, but two orders of magnitude lower detectivity compared with our devices. [ 15,45–50 ] Consequently, the devices reported in the present study exhibited superior figures of merit ( R and D *) while operating in self‐powered mode.…”

“…The higher detectivity of the 2T‐CVD devices was consistent with their higher photocurrent response (Figure 3c–f) and reflected the superior morphology, higher mobility, and longer PL lifetime of the corresponding MBI films. The responsivity, specific detectivity, and external quantum efficiency (EQE) of the 1T‐CVD and 2T‐CVD MBI photodetectors are compared with the literature implementations of bismuth‐based perovskite‐inspired photodetectors in Table 1 . [ 15,45–54 ] The responsivities (R) of the devices fabricated via both CVD processes were approximately 2 orders of magnitude higher than those of devices based on relevant organic‐inorganic hybrid films at zero bias. [ 46 ] Additionally, all devices based on inorganic double perovskites have similar responsivity, but two orders of magnitude lower detectivity compared with our devices.…”

Two‐Dimensional Bis(dithiolene)iron(II) Self‐Powered UV Photodetectors with Ultrahigh Air Stability

“…We found that the dissociation rate of the Fe(NH 4 ) 2 (SO 4 ) 2 salt is relatively slow, which promotes high‐aspect‐ratio film growth as a stabilizing effect, consistent with the density functional theory (DFT) calculations. In addition to its good durability, the unencapsulated FeBHT device exhibited the highest air stability reported so far for self‐powered photodetectors equipped with organic–inorganic hybrid photoabsorbers (Figure S2a , Supporting Information) [ 31 , 32 , 33 ] and was comparable to all‐inorganic systems (Figure S2b , Supporting Information); [ 34 , 35 , 36 , 37 , 38 , 39 ] 94% of the photocurrent is retained after 60 days of exposure to air, which implies that the organometallic 2D nanosheets used in the laboratory research can be used in actual optoelectronic applications.…”

Progress of Lead‐Free Halide Perovskites: From Material Synthesis to Photodetector Application

“…To address these problems, tremendous efforts have been made to replace Pb 2+ with other environmentally friendly metal cations, such as Sn 2+ , Bi 3+ , Cu 2+ , Sb 3+ , and Ge 2+ . [ 18–26 ] The corresponding devices (solar cells, light emissions, etc.) have achieved many great breakthroughs.…”