G. George et Jp. Krusius, TRANSIENT-RESPONSE OF HIGH-SPEED P-I-N PHOTODIODES INCLUDING DIFFUSION EFFECTS, Solid-state electronics, 37(11), 1994, pp. 1841-1847
In top-illuminated, vertical p-i-n photodiodes where one or more of th
e interfaces is a homojunction, significant absorption can take place
outside the high-field i-region, leading to diffusion currents which c
an have a significantly slower response than currents due to absorptio
n in the i region. In this paper, we derive the transient response of
a p-i-n photodiode (including the effects of diffusion currents) for p
hotogeneration in thin p, i and n regions, for the cases of analog, im
pulse and step optical inputs. An exact solution is obtained, which ma
y be used to optimize the speed and responsivity of these photodiodes,
and in simulation studies. Design strategies to improve the performan
ce of these devices are discussed.