Authors
Ragip A Pala, Andrew J Leenheer, Michael Lichterman, Harry A Atwater, Nathan S Lewis
Publication date
2014
Journal
Energy & Environmental Science
Volume
7
Pages
3424-3430
Publisher
Royal Society of Chemistry
Description
Measurement of the photocurrent as a function of the thickness of a light absorber has been shown herein both theoretically and experimentally to provide a method for determination of the minority-carrier diffusion length of a sample. To perform the measurement, an illuminated spot of photons with an energy well above the band gap of the material was scanned along the thickness gradient of a wedge-shaped, rear-illuminated semiconducting light absorber. Photogenerated majority carriers were collected through a back-side transparent ohmic contact, and a front-side liquid or Schottky junction collected the photogenerated minority carriers. Calculations showed that the diffusion length could be evaluated from the exponential variation in photocurrent as a function of the thickness of the sample. Good agreement was observed between experiment and theory for a solid-state silicon Schottky junction measured …
Scholar articles
RA Pala, AJ Leenheer, M Lichterman, HA Atwater… - Energy & Environmental Science, 2014