200 MHZ OPTICAL SIGNAL MODULATION FROM 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 constructi on steps, critical for device stability, are also presented. The devic e, when it is reverse biased in breakdown conditions, shows a white li ght emission visible in normal daylight. The emission mechanism is sup posed 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 exp lain the dynamic behavior of the device. The device speed seems to be limited by the junction capacitance rather than by an intrinsic physic al limit of the emission mechanism. (C) 1998 American Institute of Phy sics.