A novel method for the measurement of diffusion lengths in solar cells
The minority carrier diffusion length in the base region of a solar cell is an important factor affecting the conversion efficiency and spectral response of the cell. Conventional methods for the measurement of minority carrier diffusion lengths in semiconductor materials are generally unsuitable for measurements on completed solar cells. This paper describes a simple and direct technique for the measurement of minority carrier diffusion length in solar cells, It has been applied to both single crystalline and polycrystalline silicon solar cells, and the results compared to standard surface photovoltage measurements.
Interpretation of steady-state surface photovoltage measurements in epitaxial semiconductor layers
Abstract Analysis of the steady-state surface photovoltage (SPV) method of measuring minority carrier diffusion length ( L ) has been extended to the case of an epitaxial layer on a thick substrate. In layers with thickness greater than four diffusion lengths, the measurement yields the bulk value of L . For layers thinner than 0.5 L , the measured value is that of the substrate. For intermediate thicknesses, the bulk value of L can be estimated. The method also provides a sensitive means of observing the influence of surface conditions on the absorption characteristics of silicon.
Optical and Photo-Electrical Properties of Indium Antimonide
Measurements have been made of the refractive index and absorption index of InSb by reflection methods with polarized radiation. Extensive studies of absorption constant have been made by direct transmission measurements. Both photovoltaic and photoconductive effects have been observed in InSb. At room temperature the photosensitivity extends to approximately 7.5μ, a considerably longer wavelength than for any other known material.