Spectral change of intermediate band luminescence in GaP:N due to below-gap excitation: Discrimination from thermal activationShow others and affiliations
2017 (English)In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 254, no 2, article id UNSP 1600566Article in journal (Refereed) Published
Abstract [en]
As an intermediate band (IB) originating from discrete nitrogen (N) levels is formed in GaP:N with increasing N concentration, GaP1-xNx alloy is considered to be a promising candidate for IB-type solar cells. We studied the IB luminescence of a GaP1-xNx with 0.56% N and detected carrier recombination (CR) levels by superposing a below-gap excitation (BGE) light of 1.17eV. We resolved a high-energy component of 2.15eV in the IB luminescence, I-high, from total luminescence intensity I-all. With increasing the BGE density at fixed temperature of 5K, the amount of decrease in I-high was distinctly smaller than that of simple temperature rise without the BGE at the same I-all value. We conclude that the observed intensity change of the IB luminescence due to the BGE comes not from thermal activation, but from optical excitation among the IB, conduction band, and CR levels in GaP1-xNx. It is of primal importance to understand CR levels toward determining their origins and eliminating them for realization of efficient IB-type solar cells.
Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH , 2017. Vol. 254, no 2, article id UNSP 1600566
Keywords [en]
below-gap excitation; carrier recombination; GaPN; intermediate band; photoluminescence
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:liu:diva-136342DOI: 10.1002/pssb.201600566ISI: 000394614300035OAI: oai:DiVA.org:liu-136342DiVA, id: diva2:1087900
Note
Funding Agencies|JSPS KAKENHI [24360005, 25600087]
2017-04-102017-04-102017-11-29