In semiconductor radiation detectors, leakage current is a major noise source affecting energy resolution and sensitivity. The surface passivation technology can reduce this leakage current and hence significantly enhance detector performance. Here, we demonstrate a facile way to passivate the surface of the nuclear detectors based on Methylammonium Lead Iodide (MAPbI \(_3\) ) single crystals using soaking treatment in ethanol. A dense passivation layer of PbI \(_2\) was formed on the crystal surface, significantly reducing the surface leakage current by an order of magnitude under the same voltage. The energy resolution of the MAPbI \(_3\) -based detector is therefore improved by nearly 10% for the detection of 59.5 KeV irradiated from \(^{241}\) Am. Therefore, the PbI \(_2\) passivation by ethanol-soaking treatment is proved to be an effective method to reduce leakage current and improve detection performance.
In this research, we investigated the influence of phase transition in four standard perovskite materials on the device stability under thermal cycling (TC) condition, which is listed in International Electrotechnical Commission (IEC) stability tests criteria. The evolution of morphology, phase structure and charge carrier dynamics of four type perovskite materials throughout thermal cycling were analyzed. It was found that the cubic to tetragonal phase transition of MAPbI 3 caused the quick degradation of the device, the α to δ phase transition in FAPbI 3 and FA 0.6 MA 0.4 PbI 3 resulted in sustained efficiency loss, while the FA 0.9 Cs 0.1 PbI 3 was more stable compared to above three perovskites under the same test condition. The FA 0.9 Cs 0.1 PbI 3 device retained nearly 88% of its initial efficiency after 200 temperature cycles between −30 °C and 85 °C, which could be ascribed to its successful stabilization of perovskite structure.
Long Jiang,Chengzhi Xue,Jiatian Cheng,Nan Li,Xinyu Fan,Yuanbo Yang,Tiantian Li,Liwei Li,Yucheng Liu,Jiangshan Feng,Shengzhong Frank Liu,Zhou Yang
Lead halide perovskites have emerged as promising materials for sensitive, low-dose-rate X-ray imaging. However, the dark current drift caused by ion migration poses challenges to their long-term operational stability and performances. To address this issue, we explored the synergistic effects of precursor reduction and ion migration blocking have been investigated. Reducing the precursor solution decreases the defect density, enhancing the carrier lifetime and mobility-lifetime product, thus boosting X-ray sensitivity. However, this approach alone does not effectively suppress dark current drift. By incorporating ion migration blocker, the optimized device exhibits a significantly reduced dark current drift of 3.62 × 10−4 nA cm−1 s−1 V−1, an improved X-ray sensitivity of 1.22 105 μC Gyair−1 cm−2 and a low detection limit of 3 nGyair s-1 under 12.66 V mm-1 electrical field, positioning it among the best of polycrystalline perovskite X-ray detectors. Additionally, it can capture a clear X-ray image of a metal key at an X-ray dose of 2.85 μGyair s−1, highlighting its potential for low-dose X-ray imaging applications.
危险品化学品经营许可证（带存储）