Photocurrent Spectroscopy of a Resonant Cavity Enhanced Photodetector

N. A. Lacap, E. Estacio, A. Podpod, A. Salvador


Semiconductors have various applications in devices based on their electronic and optoelectronic properties. With the need for better devices, a class of optoelectronic devices has been developed that rely on resonant cavity effects to enhance device efficiency. These devices require critical matching of the cavity resonance and the material absorption edge. At the resonant wavelengths, incident light experiencing multiple reflections at the two mirrors build up the optical field. Among these are resonant cavity enhanced (RCE) photodetectors capable of improved wavelength selectivity (Kishino et al., 1991; Salvador et al., 1994). One of the most widely used semiconductor material in devices today is the III-V semiconductor Gallium Arsenide (GaAs). Bulk GaAs and GaAs-based modulated semiconductor structures such as quantum wells, with band gap absorption around 1.5 eV are both commonly used as infrared photodetectors. Moreover, GaAs quantum well heterostructures have enhanced absorption over their bulk counterparts due to excitonic effects. In this paper, we study the features of a resonant cavity enhanced (RCE) GaAs MQW photodetector by means of photocurrent (PC) spectroscopy.

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