화학공학소재연구정보센터
Journal of Crystal Growth, Vol.413, 71-75, 2015
Solid-state tellurium doping of AllnP and its application to photovoltaic devices grown by molecular beam epitaxy
Solid-state tellurium (Te) is used as an n-type dopant of AllnP grown by molecular beam epitaxy (MBE). The carrier concentration proportionally increases with increasing Te beam equivalent pressure (BEP) up to a high doping density of 1 x 10(19) cm(-3). The incorporation of Te into AllnP results in a mirror-like surface at a moderate doping density due to its surfactant effect, while the surface roughness increased with a further rising of Te doping concentration. Furthermore, for the same In and Al flux ratio, the increase of the Te flux leads to a decreased In-content, but little effect on the alloy's disorder is observed. The highly Tv-doped AllnP was used in a GaAs solar cell as a window layer. As compared with the solar cell with the Si-doped AllnP window layer, the device with the Te-doped AllnP window layer exhibits the higher efficiency and an extended increase under concentrated solar illumination, due to the benefits of the higher doping density in the Te-doped epilayer. (C) 2014 Elsevier B.V. All rights reserved