Influence of Growth Temperature on the Characteristics of Single-Junction p–i–n InGaP Solar Cells

Single-junction p–i–n InGaP solar cells are grown at various temperatures from 620 to 700 °C by low pressure metalorganic chemical vapor deposition on GaAs (001) substrates. The short circuit current density of the p–i–n InGaP solar cells increases by up to 38.8% when the growth temperature is reduced from 700 to 620 °C, while the open circuit voltage and fill factor show relatively small changes. The external quantum efficiency, especially, in the wavelength regime below 500 nm, is improved for the p–i–n InGaP solar cells grown at lower temperatures. The improvement might be attributed to the reduced absorption loss of the photons in the n-InGaP emitter region. The highest conversion efficiency of 11.01% is attributed from the p–i–n InGaP solar cell grown at 640 °C. Electron mobility and concentration of undoped InGaP layers are investigated as a function of the growth temperature and correlated with the p–i–n InGaP solar cell performance.