III–V Nitride-Based Photodetection
Since its first introduction, the nitride-based semiconductor has played an important role in the solid-state lighting application. Many great results have been published and highly efficient light-emitting diodes (LEDs) have been demonstrated. In addition to the light-emitting capability, the nitride-based materials, including aluminum nitride (AlN), gallium nitride (GaN), and indium nitride (InN), can also be very absorptive in different wavelength ranges. The photodetection has a long history in optoelectronics. As the photons impinge upon the semiconductor, if the condition is right, the electron-hole pairs can be generated after the absorption of the photons. In addition to photodetection, the photovoltaic effect is also important for the nitride-based devices. From the photodetection point of view, any photons with a higher than band gap energy are detectable. However, for the solar cell, an optimal band gap is possible for the maximum power conversion efficiency (PCE).