Enhanced photoresponse of the CdS microwire photodetectors based on indium ion implantation

Abstract

One-dimensional nano/microstructures have garnered significant attention as the fundamental building blocks for the high-performance integrated systems. Among them, CdS microwires, due to their intriguing optoelectronic properties, hold great promise as candidates for the next generation of high-performance photodetectors. In this study, CdS microwires with wurtzite structure are synthesized using a common chemical vapor deposition method. Optical characterizations revealed that the synthesized microwires exhibited a distinct near band edge emission peak at 515 nm and a broad defect-related emission peak at approximately 650 nm. It is well-known that the intrinsic defects and impurities can significantly degrade the photoresponse properties of the CdS microwire-based photodetectors. To address this issue and enhance the device’s photoresponse performance, indium (In) ion implantation is employed to heal the intrinsic defects. Compared to the pristine CdS microwires, the CdS microwire-based photodetectors with In ion implantation demonstrated a remarkable improvement in photoresponse properties. Specifically, they exhibited a higher responsivity of 390 mA W−1 and external quantum efficiency of 119% (a 94.6-fold increase). The specific detectivity also increased to 3.82 × 107 Jones (a 13-fold increase), while the decay time improved to 652 ms (compared to 3.82 s for pristine devices). Overall, our findings highlight the effectiveness of ion implantation as a strategy to enhance the performance of CdS microwires-based photodetectors. This advancement renders them potentially applicable in integrated photonic, electronic and photoelectric systems.