Large Grains and Shallow Defect States by Early Crystal Growth Suppression for High Responsivity in Perovskite Photodetectors

Abstract

The perovskite grain growth mechanism is a key factor to be considered for the enhancement of the photovoltaic effect in efficient self-powered perovskite photodetectors (PDs). Among processes employed in morphology engineering strategies, the washing process selectively removes polar solvents, induces nucleation, and promotes the formation of intermediate perovskite phases. In this study, by exploiting on the LaMer mechanism and Weimarn theory, the washing solvent in the washing process is controlled for large perovskite grains. Efficient photodetectors sensitive to a wide range of visible light are developed using a low-density washing solvent, namely ethyl ether, which maintains a low degree of nucleation and delays crystal growth leading to the expansion of perovskite grains. Perovskite processed with ethyl ether suppresses dark current and increases the photocurrent. Notably, the suppression of early crystal growth contributes to the enhancement of specific detectivity under self-powered operation. The proposed method for controlling nucleation and perovskite growth can be used to develop highly sensitive image sensors in smart vehicles via self-powered PDs due to reduction of fuel loss.

Unveiled effects of the methylammonium chloride additive on formamidinium lead halide: expediting carrier injection from the photoabsorber to carrier transport layers through spontaneously modulated heterointerfaces in perovskite solar cells

“…S4, ESI†) and the resultant larger grain size observed in the top view of scanning electron microscopy (SEM) images (Fig. S5, ESI†) suggest that the MACl addition likely improved the bulk quality 31,32 of FAPbI 3 with a little change in their bandgap energies: both have approximately 1.53 eV (Fig. S6, ESI†).…”

Efficient noise suppression via controlling the optical cavity in near-infrared organic photoplethysmography sensors

“…A photodetector is a device that is designed to convert incoming light signals into electrical signals, while providing valuable data such as light intensity, frequency, and wavelength. [1][2][3] Various types of photodetectors that can operate at distinct wavelengths have been developed, enabling a broad spectrum of applications in fields such as health monitoring, image sensing, unmanned vehicles, and optical communication. 3,4 Notably, organic photodetectors (OPDs) based on organic materials have garnered increasing attention recently.…”