The development of GaAs solar cells began in the 1950s and has a history of more than 50 years. In 1954, the photovoltaic effect of GaAs was first discovered in the world. In 1956, lofeski J.J. and his team explored the physical properties of the best materials for manufacturing solar cells. They pointed out that the materials with eg in the range of 1.2-1.6 EV had the highest conversion efficiency. At present, the efficiency of GaAs cell in laboratory is the highest, which can reach 50%.
Is a solar cell based on silicon. According to the thickness of silicon wafer, it can be divided into crystal silicon solar cell and thin film silicon solar cell. According to the crystal shape of the materials, the crystalline silicon solar cells are of the following two types: single silicon (c-Si) and poly silicon (p-Si) solar cells; Thin film silicon solar cells are divided into three types: amorphous silicon (a-Si) thin film solar cells, microcrystalline silicon (c-Si) solar cells and poly silicon (p-Si) thin film solar cells.
The conversion efficiency of single crystal solar cell is the highest and the technology is the most mature. The highest conversion efficiency in the laboratory is 24.7% (the theoretical maximum photoelectric conversion efficiency is 25%), and the efficiency at scale production is 18% (as of 2011). It still plays a leading role in large-scale application and industrial production. However, it is difficult to reduce the cost of single crystal due to the high cost of single crystal. In order to save silicon materials, many silicon films and amorphous silicon films have been developed as the substitute products of single silicon solar cells.
We know that gallium arsenide solar materials perform better under standard test conditions, because NREL has previously verified the world record efficiency of 28.8% for one-junction solar cells and 24.1% for 1-junction of Alta equipment. However, what we want to understand is how these two materials perform in the wild. In order to study the real-world impact, the results were standardized to the efficiency, which means that the efficiency advantage of gallium arsenide over silicon was eliminated.