TY - JOUR
T1 - Optical Characterization of III-V Multijunction Solar Cells for Temperature-Independent Band Gap Features
AU - Baumgartner, Hans
AU - Oksanen, Benjamin
AU - Karha, Petri
AU - Ikonen, Erkki
N1 - Funding Information:
This work was supported by projects PV-Enerate and SolCell of EMPIR and EMRP, which are programmes co-financed by the Participating States and the European Union's research and innovation programmes.
Funding Information:
Manuscript received April 23, 2019; revised July 1, 2019; accepted July 27, 2019. Date of publication September 9, 2019; date of current version October 28, 2019. This work was supported by projects PV-Enerate and SolCell of EMPIR and EMRP, which are programmes co-financed by the Participating States and the European Union’s research and innovation programmes. (Corresponding author: Hans Baumgartner.) H. Baumgartner, B. Oksanen, and P. Kärhä are with the Metrology Research Institute, Aalto University, 02150 Espoo, Finland (e-mail: hans. [email protected]; [email protected]; [email protected]).
Publisher Copyright:
© 2011-2012 IEEE.
PY - 2019/11
Y1 - 2019/11
N2 - A recently developed method to characterize the band gap energies of III-V optosemiconductors was utilized to determine temperature-invariant band gap features of multijunction solar cells. The method is based on measuring electroluminescent spectra of the solar cells at different temperatures. The normalized spectra reveal temperature-invariant energy values of the different junctions which are further converted to band gap energies. The method utilization requires a calibrated spectroradiometer and a temperature controlled mounting base for the solar cell under test, however, no knowledge about the absolute temperature of the cell under measurement. The method was tested on GaAs and GaInP solar cells that consist of single and dual junctions. The band gap energies were also derived from spectral response measurements. The differences of the determined band gap energies from the literature values were smaller than 1.1%. Compared with other band gap determination methods, the developed method yields temperature-invariant band gap characteristics; with a known uncertainty, that separated the different junctions in a multijunction device without individual biasing for the different junctions. In addition, a temperature-independent characterization parameter ensures that the operating conditions of the device under test do not affect the results.
AB - A recently developed method to characterize the band gap energies of III-V optosemiconductors was utilized to determine temperature-invariant band gap features of multijunction solar cells. The method is based on measuring electroluminescent spectra of the solar cells at different temperatures. The normalized spectra reveal temperature-invariant energy values of the different junctions which are further converted to band gap energies. The method utilization requires a calibrated spectroradiometer and a temperature controlled mounting base for the solar cell under test, however, no knowledge about the absolute temperature of the cell under measurement. The method was tested on GaAs and GaInP solar cells that consist of single and dual junctions. The band gap energies were also derived from spectral response measurements. The differences of the determined band gap energies from the literature values were smaller than 1.1%. Compared with other band gap determination methods, the developed method yields temperature-invariant band gap characteristics; with a known uncertainty, that separated the different junctions in a multijunction device without individual biasing for the different junctions. In addition, a temperature-independent characterization parameter ensures that the operating conditions of the device under test do not affect the results.
KW - Band gap
KW - III-V solar cells
KW - light-emitting diode (LED)
KW - spectral response
KW - temperature
UR - http://www.scopus.com/inward/record.url?scp=85077517096&partnerID=8YFLogxK
U2 - 10.1109/JPHOTOV.2019.2933190
DO - 10.1109/JPHOTOV.2019.2933190
M3 - Article
AN - SCOPUS:85077517096
SN - 2156-3381
VL - 9
SP - 1631
EP - 1636
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
IS - 6
M1 - 8827497
ER -