Perovskite photodetectors (PPDs), which combine the advantages of perovskite semiconductor materials with superior optical and electronic properties and solution-processed manufacturing, have emerged as a new class of revolutionary optoelectronic devices with potential for various practical applications. Encouraged by the development of various solution-synthesis and film-deposition techniques for controlling the morphology and composition of perovskite materials with interesting optoelectronic properties, increasing research attention is focused on the development of high performance PPDs. In this review, the recent progress on emerging PPDs is comprehensively summarized from the perspective of device physics and materials science. The strategies for extending the spectral response range of PPDs and improving the performance of devices are investigated. Furthermore, the methods for realizing narrowband photodetectors are also discussed, where filter-free and self-filter narrowband PPDs are achieved based on the concept of charge collection narrowing. Meanwhile, the promising future directions in this research field are proposed and discussed, including multifunctional PPDs, perovskite–organic hybrid photodetectors, flexible and transparent PPDs, self-powered PPDs, and photodetector systems and arrays. This review provides valuable insights into the current status of highly sensitive PPDs and will spur the design of new structures and devices to further enhance their photo-detection performances and meet the need of versatility in practical application.

Recent progress on highly sensitive perovskite photodetectors

Current-density-voltage (J-V) hysteresis in perovskite solar cells (PSCs) is a critical issue because it is related to power conversion efficiency and stability. Although parameters affecting the hysteresis have been already reported and reviewed, little investigation is reported on scan-direction-dependent J-V curves depending on perovskite composition. This review investigates J-V hysteric behaviors depending on perovskite composition in normal mesoscopic and planar structure. In addition, methodologies toward hysteresis-free PSCs are proposed. There is a specific trend in hysteresis in terms of J-V curve shape depending on composition. Ion migration combined with nonradiative recombination near interfaces plays a critical role in generating hysteresis. Interfacial engineering is found to be an effective method to reduce the hysteresis; however, bulk defect engineering is the most promising method to remove the hysteresis. Among the studied methods, KI doping is proved to be a universal approach toward hysteresis-free PSCs regardless of perovskite composition. It is proposed from the current studies that engineering of perovskite film near the electron transporting layer (ETL) and the hole transporting layer (HTL) is of vital importance for achieving hysteresis-free PSCs and extremely high efficiency.

On the Current-Voltage Hysteresis in Perovskite Solar Cells: Dependence on Perovskite Composition and Methods to Remove Hysteresis

Efficient Defect Passivation for Perovskite Solar Cells by Controlling the Electron Density Distribution of Donor-π-Acceptor Molecules

One-step roll-to-roll air processed high efficiency perovskite solar cells

A Review on Additives for Halide Perovskite Solar Cells

Low‐Temperature Processed, Efficient, and Highly Reproducible Cesium‐Doped Triple Cation Perovskite Planar Heterojunction Solar Cells

Perovskite photodetectors are fabricated via structuring a perovskite/organic heterojunction with CH3NH3PbI3 and a high-mobility and stable organic semiconductor dioctylbenzothieno [2,3-b] benzothiophene (C8BTBT), which possess broad range photoresponse from ultraviolet to near-infrared, fast response, and excellent stability. The CH3NH3PbI3/C8BTBT heterojunction photodetectors exhibit an excellent ratio of photocurrent to dark current, Ilight/Idark, as high as 2.4 × 104, a high responsivity up to 24.8 AW−1, and a fast response of about 4.0 ms. Meanwhile, the photodetectors can maintain 90% performance even exposed in ambient condition without encapsulation for 20 d. In addition, the detailed mechanism is disclosed based on ultraviolet photoemission spectroscopy, steady-state photoluminescence (PL) spectra, and PL lifetime experiments. The C8BTBT layer acts as an efficient hole-extraction layer to let the holes quickly transport to the electrodes due to its perfect filling in the gaps between perovskite grains, as well as its intrinsic high mobility and the energy-level match with the CH3NH3PbI3. The stable C8BTBT layer can well play as a waterproof layer as well to prevent the perovskite CH3NH3PbI3 from the degradation. The research provides an excellent method for fabricating high-performance and stable perovskite photodetectors using perovskite/organic heterojunction.

High-Performance Broadband Perovskite Photodetectors Based on CH3NH3PbI3/C8BTBT Heterojunction

Flexible perovskite network photodetectors based on the bulk heterojunction (BHJ) of CH3NH3PbI3 and an organic semiconductor dioctylbenzothieno [2,3-b] benzothiophene (C8BTBT) have been fabricated via a simple, one-step solution process. The responsivity, detectivity, and response time as the critical parameters of CH3NH3PbI3/C8BTBT BHJ network photodetectors reach 8.1 AW−1, 2.17 × 1012 Jones, and 7.1 ms, respectively. Meanwhile, they can maintain over 70% of original performance even when exposed to ambient conditions (humidity ∼ 45%) for 50 days without encapsulation. Furthermore, the CH3NH3PbI3/C8BTBT BHJ network photodetectors fabricated on a polyethylene terephthalate (PET) substrate exhibit superior flexibility at different bending radii and large numbers of bending cycles. The photocurrent just shows a decrease of less than 5% as the devices are bent for 10 000 cycles at a small radius of 7.5 mm. The present research indicates that BHJ networks composed of perovskites and organic semiconductors open up the exciting opportunity for fabricating high-performance, low-cost, flexible electronic and optoelectronic devices.

Sichao Tong

Papers

Low‐Temperature Processed, Efficient, and Highly Reproducible Cesium‐Doped Triple Cation Perovskite Planar Heterojunction Solar Cells

High-Performance Broadband Perovskite Photodetectors Based on CH3NH3PbI3/C8BTBT Heterojunction

Flexible and air-stable perovskite network photodetectors based on CH3NH3PbI3/C8BTBT bulk heterojunction

Fully doctor-bladed planar heterojunction perovskite solar cells under ambient condition

Large-area and high-performance CH3NH3PbI3 perovskite photodetectors fabricated via doctor blading in ambient condition