Engineering the Morphology and Component via Multistep Deposition of CsPbBr₃Films toward High Detectivity and Stable Self‐Powered Photodetectors

Abstract

Self‐powered perovskite photodetectors (PDs) have attracted tremendous interest for their promising advantages such as fast response speed and high detectivity. However, they usually suffer from severe operating instability issues stemming from the poor film quality, impurity phase formation, and numerous surface defects. Herein, the high performance and stable self‐powered PD based on CsPbBr3 film is demonstrated using a multistep spin‐coating method. The annealing temperature of lead bromide (PbBr2) films and the spin‐cycles of cesium bromide (CsBr) are prioritized, which are two key factors for realizing efficient devices during multistep deposition of perovskite films. Results illustrate that these two factors affect the crystallization, covering properties, and the composition of the final film. The CsPbBr3 film prepared from PbBr2 treatment at 100 °C and CsBr spin‐coating for 8‐cycles has full coverage, higher phase purity, larger grain size, higher crystallinity, and fewer defects compared with the other counterparts. Therefore, the self‐powered PD based on optimized CsPbBr3 film achieves an excellent specific detectivity of 7.01 × 1012 Jones at 520 nm at 0 V bias voltage. In addition, 96.6% of the original photocurrent can be maintained after operating for 3600 s with 93% long‐term storage (8 weeks) in ambient air, indicating its potential applications in optoelectronics field.

A‐site Cation Exchange Enables a High‐performance CsPbBr3 Photodetector for Laser Eavesdropping Systems

“…The LDR of the device is 126.7 dB, indicating an excellent linear response over a wide irradiation range. In addition, the R and D* of the device are as high as 0.37 A/W and 1.1 × 10 13 jones, respectively (Figure 4f), surpassing most perovskite PDs, [17,30,[51][52][53][54] and the detailed comparison is shown in Table 1. Figure 4g shows the I-t curve of the device irradiated by laser with a pulse frequency of 6k Hz, revealing rise time (t rise , defined as from 10% to 90% of the saturation value) and decay time (t decay , defined as from 90% to 10% of the peak value) of 2.9 and 25.1 μs, respectively.…”

An In Situ‐Fabricated All‐Inorganic Perovskite/MoO3 Heterojunction by Chemical Vapor Deposition and Its Photoresponse Properties

“…After 8 weeks in air storage, the photocurrent of the device was maintained at 93%. [22] In contrast, films prepared by the chemical vapor deposition (CVD) method have high crystallinity and stability, as well as the ability to integrate with other materials and strong adhesion to most substrates. These features are beneficial for improving the performance of PDs.…”

Broadband Response and a Transformation between Dual‐ and Single‐Wavelength Detection in Coupled Doped‐Well Quantum Cascade Detector

“…Quantum cascade detector (QCD), as a photovoltaic device, has made itself one of the prevalent devices in infrared detection. [1][2][3][4][5] Similar to self-powered photodetectors, [6][7][8] the QCD device could operate at zero bias, resulting in low dark current and high signal-to-noise ratio (S/N). [9,10] The difference is that the QCD is an intersubband (ISB) transition device and thus has a faster response time (≈1 ps), although at the cost of quantum efficiency.…”