Electron-Selective TiO2 Contact for Cu(In,Ga)Se2 Solar Cells
نویسندگان
چکیده
The non-toxic and wide bandgap material TiO2 is explored as an n-type buffer layer on p-type Cu(In,Ga)Se2 (CIGS) absorber layer for thin film solar cells. The amorphous TiO2 thin film deposited by atomic layer deposition process at low temperatures shows conformal coverage on the CIGS absorber layer. Solar cells from non-vacuum deposited CIGS absorbers with TiO2 buffer layer result in a high short-circuit current density of 38.9 mA/cm(2) as compared to 36.9 mA/cm(2) measured in the reference cell with CdS buffer layer, without compromising open-circuit voltage. The significant photocurrent gain, mainly in the UV part of the spectrum, can be attributed to the low parasitic absorption loss in the ultrathin TiO2 layer (~10 nm) with a larger bandgap of 3.4 eV compared to 2.4 eV of the traditionally used CdS. Overall the solar cell conversion efficiency was improved from 9.5% to 9.9% by substituting the CdS by TiO2 on an active cell area of 10.5 mm(2). Optimized TiO2/CIGS solar cells show excellent long-term stability. The results imply that TiO2 is a promising buffer layer material for CIGS solar cells, avoiding the toxic CdS buffer layer with added performance advantage.
منابع مشابه
Fabrication Of Cu(In,Ga)Se2 Solar Cells With In2S3 Buffer Layer By Two Stage Process
Cu(In,Ga)Se2 thin films (CIGS) on metallic substrate (titanium, molybdenum, aluminum, stainless steel) were prepared by a two-step selenization of Co-evaporated metallic precursors in Se-containing environment under N2 gas flow. Structural properties of prepared thin film were studied. To characterize the optical quality and intrinsic defect nature low-temperature photoluminescence, were perfor...
متن کاملCu(In,Ga)Se2 FILM FORMATION FROM SELENIZATION OF MIXED METAL/METAL-SELENIDE PRECURSORS
For Cu(In,Ga)Se2 films made by the selenization of metallic precursors, Ga accumulation at the back contact prevents the achievement of high voltage solar cells. In this work, selenization of mixed metal/metal-selenide precursors has been studied with respect to the composition distribution and device performance. Precursors consisting of Cu-Se/Ga/In and (In,Ga)-Se/Cu were reacted in H2Se at 45...
متن کاملDetermination of the minority carrier diffusion length in compositionally graded Cu„In,Ga...Se2 solar cells using electron beam induced current
graded Cu„In,Ga...Se2 solar cells using electron beam induced current Gregory Brown, Vladimir Faifer, Alex Pudov, Sergey Anikeev, Eugene Bykov, Miguel Contreras, and Junqiao Wu Nanosolar, Inc, San Jose, California 95138, USA National Renewable Energy Laboratory, Golden, Colorado 80401, USA Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA...
متن کاملProperties of Cu(In,Ga) Se2 Thin Films and Solar Cells Deposited by Hybrid Process
This Article is brought to you for free and open access by the Electrical & Computer Engineering at ODU Digital Commons. It has been accepted for inclusion in Electrical & Computer Engineering Faculty Publications by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. Repository Citation Marsillac, S.; Khatri, H.; Aryal, K.; and Colli...
متن کاملDelft University of Technology Quenching Mo optical losses in CIGS solar cells by a point contacted dual-layer dielectric spacer A 3-D optical study
A 3-D optical modelling was calibrated to calculate the light absorption and the total reflection of fabricated CIGS solar cells. Absorption losses at molybdenum (Mo) / CIGS interface were explained in terms of plasmonic waves. To quench these losses, we assumed the insertion of a lossless dielectric spacer between Mo and CIGS, whose optical properties were varied. We show that such a spacer wi...
متن کامل