Characterization and Modeling of Photoconductive GaN Ultraviolet Detectors


E. Monroy, J. A. Garrido, E. Muñoz, I. Izpura, F. J. Sánchez, M. A. Sánchez-García, E. Calleja
Dpt. Ingeniería Electrónica, E.T.S.I. Telecomunicación, Politécnica, Ciudad Universitaria

B. Beaumont, Pierre Gibart
Centre de Recherche sur l'Hétéroépitaxie et ses Applications, CRHEA-CNRS

This article was received on Monday, June 9, 1997 and accepted on Thursday, July 10, 1997.

Abstract

In this work high gain GaN photoconductive UV detectors have been fabricated and characterized, and a novel gain mechanism, dominant in these detectors, is described. DC responsivities higher than 103A/W have been measured for an incident power of lW/m2 at room temperature. The photoconductive gain depends directly on the bias voltage and scales with incident power as P-k (k approxequal 0.9) for more than five decades. A decrease of both gain and k parameter with temperature has also been observed. As a consequence of the slow non-exponential transient response, AC gain measurements result in lower values for gain and k parameter, which are frequency dependent. The high responsivity, non-linear behavior and slow non-exponential transient response, are all modeled taking into account a modulation mechanism of the layer conductive volume. Such spatial modulation is due to the photovoltaic response of the potential barriers related to the surface and charged dislocations arrays.

Outline

  • Introduction
  • Devices and experimental
  • Results
  • Model and discussions
  • Conclusions
  • Acknowledgments

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    Cite this article as: MRS Internet J. Nitride Semicond. Res. 2, 12(1997).

    last updated Sunday, December 20, 1998 4:53:46 PM.

    © 1997-1998 The Materials Research Society MRS Internet Journal of Nitride Semiconductor Research
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