Why do we prefer GaAs Ge or Si?
In the early 1980s, technologists believed that gallium arsenide would eventually replace silicon in the manufacture of semiconductors. This is because electrons move 510 times faster in gallium arsenide than in silicon
1)High photoelectric conversion efficiency and high reliability
2)Advanced diffusion technology to ensure the uniformity of conversion efficiency throughout the chip
3)Using advanced PECVD film forming technology, dark blue silicon nitride is plated on the surface of the battery Anti-reflection film, uniform and beautiful color
4)Use high-quality metal paste to make back field and electrodes to ensure good conductivity
5)Low cost
But GaAs (gallium arsenide) has some better electronic properties than Si, so that GaAs can be used in applications higher than 250 GHz. If the equivalent GaAs and Si components are operated at high frequencies at the same time, GaAs will generate less noise. Also because GaAs has a higher breakdown voltage, GaAs is more suitable for operation in high-power applications than the same Si devices. Because of these characteristics, GaAs circuits can be used in mobile phones, satellite communications, microwave point-to-point connections, radar systems, and other places. GaAs was used to make Gann diodes, microwave diodes, and Gunn diodes to emit microwaves,its a material with direct energy gap, so it can be used to emit light. Si is an indirect gap material, which can only emit very weak light.
The maximum intensity of solar radiation is close to 1.5eV, In order to generate light, the radiation energy (HV) must be greater than the band gap,Therefore, semiconductors with band gap equal to or less than 1.5ev and higher absorption coefficient may provide better solar energy conversion efficiency,The band gap of Si is about 1.1eV,but the band gap of GaAs is about 1.53ev.
Although the band gap of GaAs is higher than that of Si, its performance is better because it absorbs more energy from the incident solar radiation with relatively large absorption coefficient.
Ge has a main preponderance with Si. Ge has higher electron and hole mobility and because of this Ge devices can function up to a higher rates than Si devices.