Photoelectric properties of phototransistors

A group of new equations are given in this report describing the basic DC and low frequency current-voltage characteristics of desirable phototransistors for one-dimensional model.Not only these equations can be used as a basic model of CAD for phototransistors,but they can also generally describe photoelectric properties of phototransistors.The experimental results agree quite well with the calculated value derived from these new equations.The photocurrent change in phototransistors under different voltage biased conditions is also discussed.Analysis shows that the injection photosensitive device is one of the phototransistors with the operation modes .It is found that photocurrent of the injection photosensitive devices is lower than that in the photodiodes.