We developed an analytical device model for quantum well lateral p-n juncti
on photodiodes (LJPDs), The model takes into account the features of the ca
rrier transport in LJPDs and their geometry, which ensure short transit tim
es and a low capacitance. This model is used for calculating the LJPD's cha
racteristics as functions of the signal frequency, bias voltage, and struct
ural parameters and for the estimation of the LJPD ultimate performance.