Accession Number : AD0658902

Title :   P-I-N THERMO-PHOTO-VOLTAIC DIODE,

Corporate Author : PURDUE UNIV LAFAYETTE IND SCHOOL OF ELECTRICAL ENGINEERING

Personal Author(s) : Schwartz,R. J. ; Kim,C. W.

Report Date : AUG 1967

Pagination or Media Count : 133

Abstract : A p-i-n photovoltaic structure is discussed and compared with a conventional p-n junction photovoltaic converter with respect to the efficiency of conversion. The structure consists of an intrinsic region facing the illumination source with interdigitated p and n regions located on the unilluminated surface. The purpose of using an intrinsic region is to obtain longer lifetimes and diffusion lengths. The heavily doped p and n regions result in larger recoverable voltages and higher open-circuit voltages under high intensity illumination. The use of an evaporation process, with suitable masks, allowed precise control of the dimensions of the interdigitated p-i-n structure and led to the formation of heavily doped junctions. Subsequently a low alloying temperature was used in order to maintain high lifetime in the intrinsic region. It was found that a device fabricated with use of Au-Sb-As for n-type doping, Al for p-type doping, and alloyed at 430C in a gas ambient yielded heavily doped junctions. The p-i-n structure has been analyzed as a two-dimensional boundary value problem under the assumptions of charge neutrality and quasineutrality. The analysis includes calculations of the carrier concentrations generated by photon absorption, the electric field which causes an internal voltage drop in the intrinsic region, and the current dependence of the junction voltage. The solutions are given in terms of elementary functions. The results are obtained in graphical form by means of a computer. It is shown that the area of the p-contacts should be twice as large as that of the n-contacts for an optimum performance. (Author)

Descriptors :   (*PHOTOELECTRIC CELLS(SEMICONDUCTOR), *ENERGY CONVERSION), PHOTODIODES, GERMANIUM, MANUFACTURING, SEMICONDUCTOR DEVICES, MEASUREMENT, EFFICIENCY

Subject Categories : Electrical and Electronic Equipment
      Non-electrical Energy Conversion

Distribution Statement : APPROVED FOR PUBLIC RELEASE