Photoelectric response of the variable component Ga_xIn_1−xAs_ySb_1−y nanopillar arrays under the gradient electric field

Abstract III-V antimonide Ga x In 1−x As y Sb 1−y , known for its narrow bandgap, has become a crucial material for manufacturing infrared detection devices. However, the low energy and weak emission characteristics of infrared wavelengths hinder the development of infrared photocathodes. Utilizing external electric fields to assist emission is one of the primary methods to enhance the efficiency of infrared cathodes. The work establishes a model of multi-component Ga x In 1−x As y Sb 1−y heterojunction pillar array (NPAs) photocathodes under gradient electric fields, and calculate the influence of electric field on the photoelectric performance of nanopillars by numerical analysis. The computational results indicate that external electric fields, along with internal electric fields within heterojunctions affecting carrier transport, effectively regulate the emission performance of nanopillar array cathodes. Gradient-enhanced electric field can significantly enhance the quantum efficiency of nanopillar arrays. The presence of heterojunctions’ internal electric fields allows for modulation of the quantum efficiency amplitude of nanopillars while preventing breakdown, thereby providing a theoretical basis for developing high-efficiency field-assisted infrared cathodes.