A simple theory of back surface field (BSF) solar cells
- 1 June 1978
- journal article
- conference paper
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 49 (6) , 3503-3511
- https://doi.org/10.1063/1.325262
Abstract
A theory of an n‐p‐p+ junction is developed, entirely based on Shockley’s depletion layer approximation. Under the further assumption of uniform doping the electrical characteristics of solar cells as a function of all relevant parameters (cell thickness, diffusion lengths, etc.) can quickly be ascertained with a minimum of computer time. Two effects contribute to the superior performance of a BSF cell (n‐p‐p+ junction) as compared to an ordinary solar cell (n‐p junction). The sharing of the applied voltage among the two junctions (the n‐p and the p‐p+ junction) decreases the dark current and the reflection of minority carriers by the builtin electric field of the p‐p+ junction increases the short‐circuit current. The theory predicts an increase in the open‐circuit voltage (VOC) with a decrease in cell thickness. Although the short‐circuit current decreases at the same time, the efficiency of the cell is virtually unaltered in going from a thickness of 200 μm to a thickness of 50 μm. The importance of this fact for space missions where large power‐to‐weight ratios are required is obvious.This publication has 6 references indexed in Scilit:
- A note on the assumption of quasiequilibrium in semiconductor junction devicesJournal of Applied Physics, 1977
- Physical operation of back-surface-field silicon solar cellsIEEE Transactions on Electron Devices, 1977
- Interpretation of steady-state surface photovoltage measurements in epitaxial semiconductor layersSolid-State Electronics, 1972
- Effects of base doping and width on the JV characteristics of the n+−n−p+ structureSolid-State Electronics, 1972
- Hole-electron product of pn junctionsSolid-State Electronics, 1967
- Drift fields in photovoltaic solar energy converter cellsProceedings of the IEEE, 1963