Thin film photovoltaic technologies are developed to reduce material costs. There are several thin film technologies such as amorphous silicon or Cd/Te semiconductors. Research groups from different branches are studying on thin film technologies in GUNAM.
a-Si /mc-Si Thin Film Solar Cell Production
A new cluster tool for a-Si/mc-Si single junction and multi-junction solar production is under installation. This unique tool will be used to fabricate solar cells with 30 cm x 30 cm dimensions. It consists of 3 separate chambers for PECVD, 1 chamber for metal and TCO deposition. The system will be operational before 2011. The photo of the cluster tool is shown below:
Substrates with grown thin films are annealed in tube furnaces up to 1000 ⁰C to provide hydrogenation or crystallization as desired.
CdTe/CdS Solar Cell Production
CdTe and CdS thin films are fabricated using thermal evaporation system. CdTe solar cells are one of the most convenient thin film solar cells around the world. A PhD student in GUNAM is researching on CdTe thin film solar cells.
A new multi target sputtering system has recently been installed. CIGS thin films are produced by co-evaporation of the constituting elements. CIGS technology is one of the most common thin film PV technology in the market. The sputtering system shown in the photo has 3 different target and used for Copper, Indium Galium and Selenide material growth.
Thermal evaporation chambers are used to fabricate metal contacts to thin film solar cells. Transparent Conductive Oxides (TCO) are also going to be formed for thin film metallization by the new sputter tool
Laser Processing Tool
A multipurpose laser tool with three different wavelengths set up in GUNAM clean room. This tool is used for to scribe thin films, and to make edge isolation of wafer Si solar cells.