Tunable photoresponse properties of CuI/Si self-powered photodetectors through Zn doping engineering

•Zn doping of CuI films is achieved by a simple solution-process.•Zn doping concentration plays a key role on the quality of CuI films.•Photoresponse properties of CuI/Si self-powered photodetectors can be tuned through Zn doping concentration.•The optimized CuI/Si photodetector shows a high responsivity of 0.561 A/W at 0 V bias.•The photodetector demonstrates superior reliability and stability during 100-cycle tests.