Anomalous grain boundary physics in polycrystalline CuInSe2: The existence of a hole barrier
2003 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 91, no 26Article in journal (Refereed) Published
First-principles modeling of grain boundaries (GB) in CuInSe2 semiconductors reveals that an energetic barrier exists for holes arriving from the grain interior (GI) to the GB. Consequently, the absence of holes inside the GB prevents GB electrons from recombining. At the same time, the GI is purer in polymaterials than in single crystals, since impurities segregated to the GBs. This explains the puzzle of the superiority of polycrystalline CuInSe2 solar cells over their crystalline counterpart. We identify a simple and universal mechanism for the barrier, arising from reduced p-d repulsion due to Cu-vacancy surface reconstruction. This discovery opens up possibilities for the future design of superior polycrystalline devices.
Place, publisher, year, edition, pages
2003. Vol. 91, no 26
solar-cells, thin-films, junction formation, na, heterojunctions, depletion, silicon, surface, model
IdentifiersURN: urn:nbn:se:kth:diva-23066ISI: 000187719300044OAI: oai:DiVA.org:kth-23066DiVA: diva2:341764
QC 201005252010-08-102010-08-10Bibliographically approved