TiN Electrode for High-Performance CsPbBr₃ Perovskite Nanocrystal-Based Photodetectors

Solution-processed all-inorganic lead halide perovskites are widely utilized to develop photodetectors (PDs) due to their excellent optoelectronic properties. The low-cost titanium nitride (TiN) electrode not only has better corrosion resistance than Ag electrode but also possesses good conductivity comparable to Au electrode, but the utilization of TiN electrode in perovskite PDs has been rarely reported. Here, based on all-inorganic CsPbBr3 perovskite nanocrystals (NCs) synthesized through the supersaturated recrystallization method, a high-performance metal–semiconductor–metal (MSM)-type PD with a photo-to-dark-current ratio (PDCR) above $10^{4}$ and a dynamic range (DR) of 164 dB was demonstrated by employing the low-cost TiN electrode. It indicates that the PD with TiN electrode maintains a dark current as low as that of PD with Au electrode, while that with Ag electrode is hundreds of times inferior. It also reflects that the photocurrent of the PD with TiN electrode is quite close to that of the Au electrode counterpart, which exhibits a 161 times improvement with respect to the PD with Ag electrode. Moreover, the TiN electrode PD demonstrates a much better stability relative to the device with Ag electrode. Our work contributes to developing low-cost, high-performance PDs based on solution-processed semiconductors.