SANYO Electric Co., Ltd. is pleased to announce the realization of a 22.8% cell energy conversion efficiency, for a research-level HIT solar cell*1. This comes close to the world’s best conversion efficiency of 23.0% in a practical size (100 cm2 or more) announced in May 2009. SANYO’s solar cell improvement was realized using a cell thickness of 98?m, which is less than half*2 the previous thickness.
With crystalline silicon-type photovoltaic cells such as HIT solar cells, the most important issue for reducing the cost of photovoltaic systems is the achievement of both energy conversion efficiency and a thin silicon wafer, which is the energy generation layer.
Generally, reducing the thickness of the silicon wafer in order to save resources and reduce costs results in less optical absorption and causes energy conversion efficiency to drop. Now SANYO has developed technology that can greatly control the drop in performance, which has been the issue for making even thinner cells.
SANYO did this by using its technology for high efficiency creation developed over many years for its HIT solar cells, which feature high energy conversion efficiency. As a result, SANYO has achieved the world’s highest-level*3 conversion efficiency of 22.8%*4 at the research level in a practical size, using an ultra-thin HIT solar cell with a thickness of 98?m, which is less than half the thickness of a conventional high-efficiency solar cell. In the future,
SANYO will focus on advancing applications for mass-production products with technology that offers both high conversion efficiency and a thinner cell for the newly improved HIT solar cell. At the same time, the company will pursue R?D that aims for even better high conversion efficiency, lower costs, and resource-saving designs.
*1 The Heterojunction with Intrinsic Thin-layer (HIT) solar cell is an original technology developed by SANYO, and is a hybrid model that combines a crystalline silicon substrate and an amorphous silicon thin film. It offers the world’s best power generation level per unit of installation area, based on superior high energy conversion efficiency and temperature resistance.
*2 98?m, which is less than half the thickness of the world’s highest efficiency HIT solar cell (thickness > 200?m; 23.0% conversion efficiency)
*3 As of September 18, 2009 (according to in-house surveys). World’s highest conversion efficiency is 23.0% with the HIT solar cell (announced by SANYO on May 22, 2009)
*4 Evaluation results provided by the National Institute of Advanced Industrial Science and Technology (AIST).