Study of photocurrent generation in InP nanowire-based p+–i–n+ photodetectorsShow others and affiliations
2014 (English)In: Nano Reseach, ISSN 1998-0124, E-ISSN 1998-0000, Vol. 7, no 4, p. 544-552Article in journal (Refereed) Published
Abstract [en]
We report on electrical and optical properties of p+-i-n+ photodetectors/solar cells based on square millimeter arrays of InP nanowires grown on InP substrates. The study includes a sample series where the p+-segment length was varied between 0 and 250nm, as well as solar cells with 9.3% efficiency with similar design. The electrical data for all devices display clear rectifying behavior with an ideality factor between 1.8 and 2.5 at 300K. From spectrally resolved photocurrent measurements, we conclude that the photocurrent generation process depends strongly on the p+-segment length. Without p+-segment, photogenerated carriers funneled from the substrate into the NWs contribute strongly to the photocurrent. Adding a p+-segment decouples the substrate and shifts the depletion region, and collection of photogenerated carriers, to the nanowires, in agreement with theoretical modeling. In optimized solar cells, clear spectral signatures of interband transitions in the ZB and WZ InP layers of the mixed-phase i-segments are observed. Complementary electroluminescence, TEM as well as measurements of the dependence of the photocurrent on angle of incidence and polarization, support our interpretations. © 2014 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
Place, publisher, year, edition, pages
Beijing & Berlin/Heidelberg: Tsinghua University Press & Springer Verlag Berlin/Heidelberg , 2014. Vol. 7, no 4, p. 544-552
Keywords [en]
photodetectors, nanowires, solar cells
National Category
Mathematics Other Medical Sciences
Identifiers
URN: urn:nbn:se:hh:diva-25121DOI: 10.1007/s12274-014-0422-2ISI: 000339891100011Scopus ID: 2-s2.0-84899915356OAI: oai:DiVA.org:hh-25121DiVA, id: diva2:713165
Note
The authors acknowledge financial support from the Nanometer Structure Consortium nmC@LU, Halmstad University, the Erik Johan Ljungberg Foundation, the Carl Trygger Foundation, the Swedish Research Council, the Swedish National Board for Industrial and Technological Development, the Swedish Foundation for Strategic Research, the Swedish Energy Agency and the EU program AMON-RA (No. 214814).
2014-04-222014-04-182022-09-13Bibliographically approved