A reduced-dimensional polar hybrid perovskite for self-powered broad-spectrum photodetection.

Junhua Luo,Yu Peng,Shiguo Han,Dong Li,Maochun Hong,Xitao Liu,Lina Li,Xiaoqi Li,Wentao Wu

doi:10.1039/d0sc06112c

Abstract

Polar hybrid perovskites have been explored for self-powered photodetection benefitting from prominent transport of photo-induced carriers and the bulk photovoltaic effect (BPVE). However, these self-powered photodetection ranges are relatively narrow depending on their intrinsic wide bandgaps (>2.08 eV), and the realization of broad-spectrum self-powered photodetection is still a difficult task. Herein, we successfully obtained a polar multilayered perovskite, (I-BA)2(MA)2Pb3I10 (IMP, MA+ = methylammonium and I-BA+ = 4-iodobutylammonium), via rational dimension reduction of CH3NH3PbI3. It features the narrowest bandgap of 1.71 eV in a BPV material. As a consequence, the integration of narrow bandgap and BPVE causes the self-powered photodetection to extend to 724 nm for IMP, and a repeatable photovoltaic current reaching 1.0 μA cm−2 is acquired with a high “on/off” ratio of ∼103 and photodetectivity (∼109 Jones) at zero bias. This innovative research provides a foothold for adjusting the physical properties of hybrid perovskites and will expand their potential for self-powered broad-spectrum detection.

Highlights

It is well known that the inorganic layer is one of the determinants of the bandgap of a hybrid perovskite,[29,30,31,32,33] and a multilayered I-based perovskite with a polar structure is promising to acquire a narrow bandgap toward broad-spectrum self-powered photodetection
The organic MA+ cations reside in the cavities formed by the corner-sharing PbI6 octahedra, and I-BA+ is the “spacer” that is con ned in the interlayer space of the inorganic sheets
It's worth noting that both con ned MA+ and I-BA+ cations are ordered at room temperature in IMP, and are different to MA+ cations in the typical 3D perovskites that are highly disordered and random in the cavities

Summary

Introduction

Self-powered photoelectric detection is of great signi cance to next-generation miniature and cost-effective photoelectric devices.[1,2,3,4,5,6,7,8] Self-powered photodetection based on the bulk photovoltaic effect (BPVE) of polar materials has attracted intense attention recently.[9,10] Compared to the traditional selfpowered photodetectors constructed by p–n junctions or Schottky barriers,[11,12] BPVE induced self-powered photodetection eliminates the complicated interface engineering and fabrication process.[13,14] Notably, self-powered visible-blind ultraviolet photodetection depending on the BPVE has been realized in BaTiO3, (K0.5Na0.5)–(Mn0.005Nb0.995)O3, and Ladoped Pb(Zr,Ti)O3.15–17 these inorganic oxides suffer from wide bandgaps (>2.7 eV) and low concentrations of photoinduced carriers, which limit their potential detection range. A reduced-dimensional polar hybrid perovskite for self-powered broad-spectrum photodetection† Polar hybrid perovskites have been explored for self-powered photodetection benefitting from prominent transport of photo-induced carriers and the bulk photovoltaic effect (BPVE).

Results

Conclusion