The spectral response and band features of cesium-covered GaAs have been investigated by using a spectral-response measuring instrument at room temperature. We find that the shape of the spectral- response curves is almost identical if the vacuum level is greater than the energy level of the conduction band minimum; otherwise, the shape changes with time. The preservation or change in the shape is attributed to the evolution of a surface barrier. By calculation of the derivatives of the spectral response, the band features of GaAs can be determined. We find six peaks in the spectral-response derivatives. These peaks are in excellent agreement with the photon energy positions determined by the transitions from different valence band peaks to different conduction band valleys.
© 2010 Optical Society of America
Original Manuscript: February 4, 2010
Manuscript Accepted: March 26, 2010
Published: May 4, 2010
Jijun Zou, Benkang Chang, Yijun Zhang, and Zhi Yang, "Variation of spectral response from cesium-covered GaAs and band features contained within the spectral response," Appl. Opt. 49, 2561-2565 (2010)