Abstract:
Though CH3NH3PbBr3 single crystals are frequently applied in various optoelectronic devices due to their favorable cuboid geometry, superior optoelectronic properties, and better stability than CH3NH3PbI3, CH3NH3PbBr3 polycrystalline films normally show poorer morphology with scattered crystals than their iodide counterparts, inherently due to their different crystallization habits. In this work, a facile process based on a hot methylamine-based precursor with high viscosity and concentration is demonstrated to counteract rapid ion diffusion. The precursor also has special features including a large colloidal size, a solid form at room temperature, and fast crystallization offered by the easy evacuation of methylamine. CH3NH3PbBr3 films composed of tightly aligned CH3NH3PbBr3 cuboids on micron scale are obtained. Wide channel (100 μm) photodetectors made from the CH3NH3PbBr3 films show promising photoresponse and fast response speeds on par with those based on single crystals, suggesting high film quality and good optoelectronic connections between neighboring cuboids.
摘要:
尽管CH3NH3PbBr3单晶由于其有利的长方体几何形状而经常应用于各种光电器件中,优越的光电性能,和更好的稳定性比CH3NH3PbI3,CH3NH3PbBr3多晶膜通常显示较差的形态与分散晶体比他们的碘化物对应物,本质上是由于他们不同的结晶习惯。在这项工作中,证明了一种基于具有高粘度和浓度的基于热甲胺的前体的简单方法可以抵消快速的离子扩散。该前体还具有特殊功能,包括大的胶体尺寸,在室温下的固体形式,和快速结晶提供的容易疏散的甲胺。获得了由微米级紧密排列的CH3NH3PbBr3长方体组成的CH3NH3PbBr3薄膜。由CH3NH3PbBr3薄膜制成的宽通道(100μm)光电探测器显示出与基于单晶的光电响应和快速响应速度相当的前景,这表明相邻长方体之间的膜质量高,光电连接良好。