Comparison of CIGS solar cells made with different structures and fabrication techniques

Journal Article · Thu Nov 03 00:00:00 EDT 2016 · IEEE Journal of Photovoltaics

DOI:https://doi.org/10.1109/JPHOTOV.2016.2616188· OSTI ID:1357739

Mansfield, Lorelle M. ^[1]; Garris, Rebekah L. ^[1]; Counts, Kahl D. ^[2]; Sites, James R. ^[2]; Thompson, Christopher P. ^[3]; Shafarman, William N. ^[3]; Ramanathan, Kannan ^[1]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Colorado State Univ., Fort Collins, CO (United States)
3. Univ. of Delaware, Newark, DE (United States)

Cu(In, Ga)Se2 (CIGS)-based solar cells from six fabricators were characterized and compared. The devices had differing substrates, absorber deposition processes, buffer materials, and contact materials. The effective bandgaps of devices varied from 1.05 to 1.22 eV, with the lowest optical bandgaps occurring in those with metal-precursor absorber processes. Devices with Zn(O, S) or thin CdS buffers had quantum efficiencies above 90% down to 400 nm. Most voltages were 250-300 mV below the Shockley-Queisser limit for their bandgap. Electroluminescence intensity tracked well with the respective voltage deficits. Fill factor (FF) was as high as 95% of the maximum for each device's respective current and voltage, with higher FF corresponding to lower diode quality factors (~1.3). An in-depth analysis of FF losses determined that diode quality reflected in the quality factor, voltage-dependent photocurrent, and, to a lesser extent, the parasitic resistances are the limiting factors. As a result, different absorber processes and device structures led to a range of electrical and physical characteristics, yet this investigation showed that multiple fabrication pathways could lead to high-quality and high-efficiency solar cells.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1357739
• Report Number(s): NREL/JA-5K00-66492
• Journal Information: IEEE Journal of Photovoltaics, Vol. 7, Issue 1; ISSN 2156-3381
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
auger electron spectroscopy (AES)
capacitance
characterization
correlation
Cu(In
Ga)Se2 (CIGS)
internal quantum efficiency
thin-film photovoltaics