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.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics