NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Key factors limiting the open circuit voltage of n(+)pp(+) indium phosphide solar cellsSolar cells made from gallium arsenide (GaAs), with a room temperature bandgap of E(sub g) = 1.43 eV have exhibited the best measured open circuit voltage (V sub OC) of 1.05 V at 1 AMO, 25 C. The material InP is in many ways similar to GaAs. A simple calculation comparing InP to GaAs then shows that solar cells made from InP, with E(sub g) = 1.35 at 300 K, should exhibit the best measured (V sub OC) of approximately 950 mV at 1 AMO, 300 K. However, to date, the best measured V(sub OC) for InP solar cells made by any fabrication method is 899 mV at AM1.5, 25 C which would translate to 912 mV at 1 AMO, 25 C. The V(sub OC) of an n(+)pp(+) InP solar cell is governed by several factors. Of these, some factors, such as the thickness and doping of the emitter and base regions, are easily controlled and can be adjusted to desired values dictated by a good performance optimizing model. Such factors were not considered. There are other factors which also govern V(sub OC), and their values are not so easily controlled. The primary ones among these are (1) the indirect or Hall-Shockley-Read lifetimes in the various regions of the cell, (2) the low-doping intrinsic carrier concentration n(sub i) of the InP material, (3) the heavy doping factors in the emitter and BSF regions, and (4) the front surface recombination velocity S(sub F). The influence of these latter factors on the V(sub OC) of the n(+)pp(+) InP solar cell and the results were used to produce a near-optimum design of the n(+)pp(+) InP solar cell.
Document ID
19910009893
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Goradia, Chandra
(Cleveland State Univ. OH., United States)
Thesling, William
(Cleveland State Univ. OH., United States)
Weinberg, Irving
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1991
Publication Information
Publication: Space Photovoltaic Research and Technology, 1989
Subject Category
Energy Production And Conversion
Accession Number
91N19206
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available