Graded Bandgap Solar Cells

Abstract

This program has emphasized investigations of graded bandgap solar cells. The key objective was to determine the feasibility of obtaining high efficiencies with a graded emitter heterojunction structure. The Al(x)Ga(1-x) As ternary system was selected for actual device fabrication and characterization. Interpretation of photoresponse data for graded devices indicated that the minority carrier diffusion length was essentially zero for x equal to or greater than .25. This property of the AlGaAs films made it impossible to obtain the expected photocurrent from the graded devices. However, studies were carried out which clearly indicated that the structures with graded emitters were characterized by an enhanced photoresponse relatice to homojunction devices.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1989
Accession Number
ADA211537

Entities

People

  • Larry C. Olsen

Organizations

  • University of Washington

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Band Structures
  • Cell Structure
  • Cells
  • Chemical Vapor Deposition
  • Classification
  • Diffusion
  • Efficiency
  • Electron Holes
  • Electrons
  • Fabrication
  • Heterojunctions
  • Materials
  • Minority Groups
  • Radiation
  • Security
  • Solar Cells
  • Solar Energy

Fields of Study

  • Materials science

Readers

  • Semiconductor Device Technology