Solar Blind Photodetector Based On Epitaxial Zinc Doped Ga2O3 Thin Film

Keywords

MOCVD; responsivity; solar blind photodetector; zinc doped β-Ga O thin film 2 3; β-Ga O thin film 2 3

Abstract

We report on the fabrication and characterization of solar blind photodetectors (SBPs) based on undoped β-Ga2O3 and Zn doped (∼5 × 1020 cm−3) β-Ga2O3 (ZnGaO) epitaxial films with cutoff wavelength of ∼260 nm. The epilayers were grown on c-sapphire by the metal organic chemical vapor deposition technique and their structural, electrical and optical properties were characterized using various methods. As grown films have a large number of defects, resulting in detectors with enhanced internal gain, hence, high spectral responsivity >103 A/W. Post growth annealing in oxygen improved the quality of the epilayers, leading to detectors with reduced dark current (∼nA to ∼pA) and increased out of band rejection ratio. At 20 V bias, a ZnGaO detector showed a peak responsivity of 210 A/W (at 232 nm) and an out of band rejection ratio (i.e., R232 nm/R320 nm) of 5 × 104. Alternatively, for a β-Ga2O3 detector these parameters were found to be five times and three times lower, respectively, suggesting that ZnGaO detectors have superior performance characteristics. These results provide a roadmap toward achieving high responsivity SBPs based on epitaxial ZnGaO films, laying a solid foundation for future applications.

Publication Date

5-1-2017

Publication Title

Physica Status Solidi (A) Applications and Materials Science

Volume

214

Issue

5

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1002/pssa.201600688

Socpus ID

85008215934 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85008215934

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