溴铅铯（CsPbBr3）具有原子序数高、密度大、禁带宽的特点，尤其是CsPbBr3单晶中电子和空穴具有大的且数量级相同的载流子迁移率寿命积，这些优良物理特性使其成为一种极具潜力的新型三元化合物半导体室温核辐射探测候选材料。与目前广泛采用的三元化合物CdZnTe相比，溴铅铯熔点低易于熔融生长，能克服由于熔点高易出现成分起伏及沉淀相等的缺点。本项目拟采用具有自主知识产权的垂直温度梯度凝固法生长CsPbBr3单晶，解决布里奇曼法或区熔法因需移动安瓿或加热器易产生温度波动导致组分起伏及结晶热应力等缺陷的问题。系统研究化学计量比、温度梯度、生长速率等关键参数对晶体生长的固液界面、晶体组分均匀性及完整性的影响。结合各种表征手段来研究CsPbBr3晶体生长动力学及缺陷热力学，控制晶体热缺陷的产生，从而制备出结晶缺陷少、完整性好、光电特性优良的CsPbBr3单晶及探测器单元。

Due to its high effective atomic number, high density, wide band gap, and especially its highly optimized mobility lifetime product (μτ) values for electrons and holes in the crystals, CsPbBr3 has been discovered as a promising alternative ternary compound suitable for high energy radiation detection. Compared with CdZnTe (CZT), a leading nuclear radiation detector material, CsPbBr3 displays lower melt point and simpler crystal growth conditions, and therefore it has the merit to overcome the disadvantages of the crystal growth of CZT such as composition fluctuation, as well as the formation of Te precipitates during crystal growth resulting from high melt point of CZT. In the present proposal, CsPbBr3 crystals will be grown by vertical gradient freezing method under our own intellectual property. And therefore, some problems will be circumvented that usually appear in Bridgman growth method and travelling molten zone method, for example, due to movements of ampoules or heaters, the local composition fluctuation in the solid along with the wide difference in the lattice constants and the thermal expansion coefficients of constituent binary compounds introducing considerable strain. The influence of several key parameters, such as stoichiometric ratio, temperature gradient, and growth rate on the shape of solid-liquid boundary, homogeneity in composition, and crystal perfection of the as-grown crystals will be systematically investigated. To understand the mechanism of the crystal growth and to obtain CsPbBr3 crystals with less defects, good perfection, and good electrical and optical characteristics, the dynamics of crystal growth and thermodynamics of defects will be investigated through various characterization. The aim of this research is to obtain high quality single crystals and room-temperature detectors with good time stability, good energy resolution and high detection efficiency.