We have developed a much safer metalorganic chemical vapor phase epitaxy (MOVPE) process with all liquid phase organic precursors without using hazardous gases including doping sources. In this study, the silicon doping in GaAs grown using tetraethylsilane with tertiarybutylarsine has been investigated. Excellent controllability and reproducibility of n-type doping level from 1 X 10(17) to 6 X 10(18) cm(-3) with low carbon incorporation are confirmed. The carrier concentration increases with increasing growth temperature and decreases with increasing V/III ratio. In addition, we applied the MOVPE process with all liquid sources for the fabrication of the GaAs solar cell, and obtained good cell performance of over the conversion efficiency of 20%.