The effect of the PbI _2 surface passivation on the leakage current for MAPbI _3 single crystal nuclear detectors

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