论文信息 - BGaInAs solar cells lattice-matched to GaAs

BGaInAs solar cells lattice-matched to GaAs

The authors have recently demonstrated the epitaxial growth of B/sub x/Ga/sub 1-x-y/In/sub y/As on GaAs substrates by metal-organic chemical vapor deposition. This new material has a bandgap less than that of GaAs, and can be grown lattice-matched to GaAs. Such a material, used as the second or third junction in a strain-free multijunction III-V solar cell, has the potential to increase the total cell efficiency. They report here on the performance of single-junction solar cells with 1.36-eV carbon- and silicon-doped B/sub 0.03/Ga/sub 0.91/In/sub 0.06/As bases and compare them with similar GaAs and Ga/sub 0.94/In/sub 0.06/As cells. The BGaInAs cells have exhibited less-than-ideal open-circuit voltages (V/sub oc/ and fill factors) (FF) of 0.57-0.66 V and 69%-73%, respectively. Poor red response of the quantum efficiencies and low short-circuit currents (j/sub sc/) of 10-14 mA/cm/sup 2/ under AM1.5D conditions indicate that the minority-carrier diffusion lengths are short (<0.1 /spl mu/m). The n-on-p devices perform slightly better than the p-on-n devices.

[1] John F. Geisz,et al. Modeling of electron diffusion length in GaInAsN solar cells , 2000, Conference Record of the Twenty-Eighth IEEE Photovoltaic Specialists Conference - 2000 (Cat. No.00CH37036).

[2] Eric Daniel Jones,et al. InGaAsN solar cells with 1.0 eV band gap, lattice matched to GaAs , 1999 .

[3] Daniel J. Friedman,et al. Photocurrent of 1 eV GaInNAs lattice-matched to GaAs , 1998 .

[4] Sarah R. Kurtz,et al. 1-eV solar cells with GaInNAs active layer , 1998 .

[5] John F. Geisz,et al. BGaInAs alloys lattice matched to GaAs , 2000 .

[6] Daryl R. Myers,et al. Projected performance of three- and four-junction devices using GaAs and GaInP , 1997, Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997.

[7] R. Newman. Chapter 4 Local Vibrational Mode Spectroscopy of Defects in III/V Compounds , 1993 .

[8] John F. Geisz,et al. Epitaxial growth of BGaAs and BGaInAs by MOCVD , 2001 .

[9] K. Emery,et al. Triple-junction solar cell efficiencies above 32%: the promise and challenges of their application in high-conceniration-ratio PV systems , 2000, Conference Record of the Twenty-Eighth IEEE Photovoltaic Specialists Conference - 2000 (Cat. No.00CH37036).

[10] Eric Daniel Jones,et al. Minority carrier diffusion, defects, and localization in InGaAsN with 2% nitrogen , 2000 .