Study of RE-Doped InGaN Semiconductor Heterostructures for Photocathodes

POSTER

Abstract

Photocathodes, devices that emit electrons when illuminated, are vital for generating high-brightness and spin-polarized electron beams in accelerator physics. Indium gallium nitride (InGaN) heterostructures are promising next-generation photocathode materials due to their tunable bandgap, high quantum efficiency, and chemical robustness under extreme conditions. However, structural defects such as point defects and dislocations introduce electronic states in the bandgap that degrade emission efficiency and carrier transport. This project surveys current literature on InGaN-based photocathodes, focusing on the role of rare-earth (RE) doping and defect control. Using advanced characterization techniques, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-VIS spectroscopy, Raman, FTIR, and Hall effect measurements, we assess how defects impact band structure, optical behavior, and electrical performance. These insights guide the design of RE-doped InGaN heterostructures optimized for durable, high-performance photocathodes in accelerator systems.

*This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, Reaching a New Energy Sciences Workforce (NP-RENEW). I'd like to thank Palai for helping me throughout my project and the OEP for funding my summer internship. The research described herein is Fundamental Research as defined in the ITAR (22 CFR 120.34(a)(8)), EAR (15 CFR 734.8), or Part 810 (10 CFR 810.3), as applicable, and as described in the USD (AT&L) memoranda on Fundamental Research, dated May 24, 2010, and on Contracted Fundamental Research, dated June 26, 2008.

Presenters

  • Juan C Velez Reyes

    • University of Puerto Rico Rio Piedras

Authors

  • Juan C Velez Reyes

    • University of Puerto Rico Rio Piedras
  • Palai Ratnakar

    • Mentor
  • Luca Cultrera

    • Mentor
    • Brookhaven National Laboratory