Chen Weiwei, Hao Jiongyue, Hu Wei, Zang Zhigang, Tang Xiaosheng, Fang Liang, Niu Tianchao, Zhou Miao
Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), College of Optoeletronic Engineering, Chongqing University, Chongqing, 400044, China.
Department of Applied Physics, College of Physics, Chongqing University, Chongqing, 401331, China.
Small. 2017 Jun;13(21). doi: 10.1002/smll.201604085. Epub 2017 Apr 13.
All-inorganic perovskite CsPbX (X = Cl, Br, I) and related materials are promising candidates for potential solar cells, light emitting diodes, and photodetectors. Here, a novel architecture made of CsPbX /ZnS quantum dot heterodimers synthesized via a facile solution-phase process is reported. Microscopic measurements show that CsPbX /ZnS heterodimer has high crystalline quality with enhanced chemical stability, as also evidenced by systematic density functional theory based first-principles calculations. Remarkably, depending on the interface structure, ZnS induces either n-type or p-type doping in CsPbX and both type-I and type-II heterojunctions can be achieved, leading to rich electronic properties. Photoluminescence measurement results show a strong blue-shift and decrease of recombination lifetime with increasing sulfurization, which is beneficial for charge diffusion in solar cells and photovoltaic applications. These findings are expected to shed light on further understanding and design of novel perovskite heterostructures for stable, tunable optoelectronic devices.
全无机钙钛矿CsPbX（X = Cl、Br、I）及相关材料是潜在太阳能电池、发光二极管和光电探测器的有前景的候选材料。在此，报道了一种通过简便的溶液相法合成的由CsPbX/ZnS量子点异质二聚体制成的新型结构。微观测量表明，CsPbX/ZnS异质二聚体具有高结晶质量且化学稳定性增强，基于密度泛函理论的系统第一性原理计算也证明了这一点。值得注意的是，根据界面结构，ZnS在CsPbX中诱导n型或p型掺杂，并且可以实现I型和II型异质结，从而导致丰富的电子特性。光致发光测量结果表明，随着硫化程度的增加，会出现强烈的蓝移和复合寿命的降低，这有利于太阳能电池中的电荷扩散和光伏应用。这些发现有望为进一步理解和设计用于稳定、可调谐光电器件的新型钙钛矿异质结构提供启示。
