Photovoltage-distance dependence and a method for parametric optoelectronic measurements

Abstract

With the present worldwide interest for the manufacture of inexpensive solar cells, compound semiconductor lasers, etc. and for the universal transmission and reception if information, optoelectronic devices and the means of characterizing them are now, as ever, of utmost importance for research and development.
The usual method of characterization of optoelectronic prototypes, components, or devices such as solar cells, photodiodes, phototransistors, etc. is by measuring the I-V characteristics under dark, and under illumination of a variable intensity about AM1 from a quartz-halogen or tungsten lamp with a Si cell as standard.
In this work, a different approach is proposed based on some theoretical considerations that involve basically the following:
(1) A modified form of irradiance inverse square law;
(2) The photogenerated-current equation;
(3) The I-V characteristic equation of the p-n junction of a semiconductor device such as a photodiode, phototransistor, photovoltaic or solar cell, etc.
By interrelating these laws, a photovoltage-distance relation of the following form is theoretically derived: V = A - Bz².