LPE法生长GaP/Si材料初探

用普通的液相外延(LPE)方法,在Si衬底上生长了厚约10μm的GaP外延层,并对以Ga,In或Sn为生长熔体进行生长得到的结果做了比较.结果表明,Si在Ga中溶解度很大,Ga不适合做熔体;In为熔体时生长出InGaP合金,Si含量较高,而且出现化学计量比偏离现象;Sn为熔体生长的GaP层中Si含量小于In熔体,而且GaP符合化学计量比.

Steady-state solution growth of microcrystalline silicon on nanocrystalline seed layers on glass

The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented.This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics.

硅液相外延的溶剂选择

本文系统综述了硅液相外延中对各种溶剂的选择。重点叙述了Cu、Ga、Au、In、Sn、Pb等纯金属及Ag基、Au基、Al基合金作为溶剂,对硅液外延薄膜的影响。最后指出只要根据器件对外延层及工艺成本等的要求,可以找到适当的溶剂材料进行硅液相处延。

p型掺杂晶体硅的低温液相(001)外延生长研究

为寻求以低成本制备n型太阳电池的pn结,进行了Al-17.6wt%Si合金熔体中(001)n型单晶硅衬底上液相外延生长p型掺杂硅实验。所用方法为垂直浸渍法,实验了过冷恒温生长与回熔处理后连续冷却生长两种模式,过程中体系以流动高纯氩保护。对所得外延生长晶体结构、形貌及所得pn结开路电压进行了分析和测定。结果显示,合金熔体中硅晶体(001)液相外延生长能够实现,但一般呈离散分布的金字塔型岛状生长;只有衬底回熔处理后原位连续降温生长模式可获得连续外延薄膜,之后在其上出现岛状生长,呈现Stranski-Krastanov生长模式。所得连续外延薄膜形成的pn结开路电压比恒温生长所得的提升约100 m V;连续外延薄膜形成后期出现的岛状生长使开路电压明显下降;生长速度提高会使连续降温外延生长pn结开路电压略有降低。