氧气对CsPbBr_(3)单晶电学性能的影响

Effect of Oxygen on Electrical Performance of CsPbBr_(3) Single Crystal

CsPbBr_(3)兼具高探测效率和较好的稳定性,是当前高性能高能辐射探测器的热门材料。在使用坩埚下降法制备CsPbBr_(3)单晶的配料阶段,如果无法有效隔绝原料与氧气的接触,氧气会吸附于原料表面难以排出,在原料熔化后会聚集在密封坩埚的上方,导致所得到的单晶颜色沿生长方向逐渐变深,这一颜色变化不会改变CsPbBr_(3)的禁带宽度。通过对单晶上端切片进行电学性能测试发现,从单晶的中心到外侧,CsPbBr_(3)单晶的电阻率逐渐下降,陷阱密度和载流子迁移率逐渐增大,但对X射线的响应度基本不变。本文为研究高质量CsPbBr_(3)单晶的生长提供帮助。

CsPbBr_(3)is a promising material for high-performance high-energy radiation detectors with high detection efficiency and good stability.In the ingredient stage of preparing the CsPbBr_(3)single crystal by the vertical Bridgman technique,the oxygen will adsorb on the surface of raw materials,and gather above the sealed crucible after melting,if the contact between the raw material and the oxygen cannot be effectively isolated,and results in a gradually darker color of the single crystal along the growth direction.The color change does not change the band gap of the CsPbBr_(3).The electrical performance test of the upper end section of CsPbBr_(3)single crystals reveals that the resistivity gradually decreases,and the trap density and carrier mobility gradually increases from the center to the outside of CsPbBr_(3)single crystals.But the responsiveness to X-rays is unchanged from the center to the outside of CsPbBr_(3)single crystals.This paper contributes to studies on the growth of high-quality CsPbBr_(3)single crystals.