基于固-气反应方法制备硫化物半导体薄膜及光伏器件

In this project, a new technology is developed for the deposition of sulfide semiconductor thin films (or quantum dots) on mesoporous or planar titanium dioxide (or zinc oxide) for sensitization of the wide gap semiconductors. The technology is based on the in-situ reaction of solid-gas: a semiconductor precursor is first deposited on the substrate, followed by reaction with H2S gas. The preparation method is simple, facile, and the thickness of the deposited film could be easily controlled through adjusting the concentration of the precursor and the processing parameters. In addition, the method could apply to the fabrication of binary or ternary semiconductors. More importantly, using this method, the impurity of the oxides could be excluded in the deposited films, which always exist in the films prepared by traditional solution methods such as chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR). Moreover, this method could apply to deposition of multi-layer sulfide semiconductors or different sulfide semiconductors in a single layer for the devices with different structures. The application of the deposited semiconductors could be found in photovoltaic and other optoelectronic devices.

本项目提出一种在宽带隙介孔或平面半导体（如二氧化钛，氧化锌）电极上制备无机硫化物半导体薄膜（或量子点）的新工艺，拓宽这类宽带隙电极对太阳光谱吸收和利用（在可见光和近红外区）；提出了基于原位固-气反应制备工艺：半导体前驱体溶液首先沉积到基底，然后在硫化氢气氛中通过固-气反应原位合成硫化物半导体。这种方法提供了一种快速制备硫化物半导体的新方法，工艺简单，沉积的半导体的膜厚可通过前驱体浓度和工艺参数来调控。重要的是，本项目提出的方法避免了传统溶液法（化学浴沉积和连续离子层吸附反应）产生氧化物杂质对器件性能的影响。另外，这种方法还可以拓宽到三元硫化物半导体制备，以及多层不同硫化物薄膜或层内不同硫化物共混薄膜制备，利用这种方法制备硫化物半导体薄膜可在光伏电池以及其它光电子器件上获得应用。

本课题基于固-气反应方法，成功制备二元硫化物和三元硫化物半导体薄膜及光伏器件；同时我们进一步利用固-气反应方法在铅钙钛矿薄膜和光伏器件，以及锡钙钛矿薄膜和光伏器件方面开展了研究，并取得重要进展。研究表明，与常规的量子点预合成或原位沉积方法制备无机半导体相比较，固-气反应方法提供制备高质量无机半导体薄膜和器件的一种简单和有效的方法，同时这种方法可以拓宽到无机/有机杂化半导体薄膜和器件的制备。