200 MHz optical signal modulation a porous silicon light emitting device

The light emission frequency response of an extremely stable Schottky (Al-porous silicon) light emitting device is presented. The construction steps, critical for device stability, are also presented. The device, when it is reverse biased in breakdown conditions, shows a white light emission visible in normal daylight. The emission mechanism is supposed to be the radiative transition of hot electrons generated in the breakdown process. The optical signal modulation has been measured up to 200 MHz and a simple electrical model is presented in order to explain the dynamic behavior of the device. The device speed seems to be limited by the junction capacitance rather than by an intrinsic physical limit of the emission mechanis