Investigation on the interface electric field of aluminum-doped zinc oxide/p-type gallium arsenide (AZO/p-GaAs) heterojunctions for terahertz emission applications

  • Erick John Carlo D Solibet National Institute of Physics, University of the Philippines Diliman
  • Archel Susvilla Escaro National Institute of Physics, University of the Philippines Diliman
  • Lorenzo Lopez, Jr. National Institute of Physics, University of the Philippines Diliman and Materials Science and Engineering Program, University of the Philippines Diliman
  • Angela Faustino National Institute of Physics, University of the Philippines Diliman and Materials Science and Engineering Program, University of the Philippines Diliman
  • Hannah Rillera National Institute of Physics, University of the Philippines Diliman and Materials Science and Engineering Program, University of the Philippines Diliman
  • Neil Irvin Cabello National Institute of Physics, University of the Philippines Diliman
  • Alexander De Los Reyes National Institute of Physics, University of the Philippines Diliman
  • Elmer Estacio National Institute of Physics, University of the Philippines Diliman
  • Armando Somintac National Institute of Physics, University of the Philippines Diliman
  • Arnel Salvador National Institute of Physics, University of the Philippines Diliman
Keywords: III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions 73.40.Kp, photoemission of heterostructures (79.60.Jv), spray pyrolysis (68.55.A), ultrafast spectroscopy (condensed matter) 78.47.hj

Abstract

Aluminum-doped zinc oxide (AZO) films were deposited on p-type GaAs substrates with different Al% via spray pyrolysis to investigate the dependence of terahertz (THz) emission on the interface electric field of AZO/p-GaAs heterostructures. Photoreflectance spectroscopy was used to measure the electric field at the interface of the heterojunctions. Reflection-geometry THz time-domain spectroscopy showed that the THz intensity gradually increases with Al doping and peaks at 2% Al, which coincides with the maximum electric field. Comparison of THz intensity and electric field confirms that the THz emission in AZO/p-GaAs is governed by photocarrier drift. In addition, it was shown that photocarrier drift is a dominant factor in the observed THz intensity enhancement.

Published
2017-06-07
Section
Poster Session A (Experimental Materials Science and Photonics)