大尺寸CH_(3)NH_(3)PbBr_(3)晶体生长和光电性能表征

Growth and Photoelectric Properties Characterization of Large-Sized CH_(3)NH_(3)PbBr_(3) Crystal

卤化物钙钛矿材料作为一种新型的半导体材料,具有材料廉价和光电转换性能优异的优点,基于该材料的各类光电器件已经开始逐步应用。虽然多晶薄膜仍然是主要的研究方向,但其具有形态无序、杂质较多的缺点,而单晶具有无晶界、低缺陷的特点,因此基于大尺寸单晶的研究开始被广泛关注。本文设计了一套内外反控温循环过滤生长装置,采用逆温结晶和籽晶相结合的方法制备了直径大于60 mm的CH_(3)NH_(3)PbBr_(3)单晶,对晶体样品进行了物相、微观形貌、光学和电学性能的研究。该晶体属于立方晶系,空间群为Pm3m;紫外-可见吸收光谱显示吸收截止边约为576 nm,荧光发射谱峰值552 nm;摇摆曲线显示晶体(100)晶面半峰全宽为91.42″。切割抛光后的晶片光响应灵敏,开关比为2.4×10^(3)。

As a new type of semiconductor material,halide perovskite materials has the advantages of low cost and excellent photoelectric conversion performance.Various photoelectric devices based on the halide perovskite materials have begun to be gradually applied.Polycrystalline thin films are still the main research direction,however,they have the disadvantages of disordered morphology and many impurities.In contrast,single crystals have the characteristics of no grain boundaries and low defects.Therefore,the research based on large-size single crystals gained widely concerned.In this paper,a set of internal and external reverse temperature control cycle filtration growth devices was designed.The CH_(3)NH_(3)PbBr_(3) single crystal with a diameter of more than 60 mm was prepared by the combination of inverse temperature crystallization and seed crystal.The phase,microstructure,and optical and electrical properties of the crystal samples were studied.The crystal belongs to the cubic system with space group of Pm3m.The ultraviolet-visible absorption spectrum shows that the absorption cut-off edge is about 576 nm and the fluorescence emission spectrum peak is 552 nm.The rocking curve shows that the half width at maximum of the crystal(100) plane is 91.42″.The wafer after cutting and polishing is sensitive to photo response,and the on-off ratio is 2.4×10^(3).