Thin-Film CIGS Photovoltaic Technology: Annual Technical Report-Phase II, 16 April 1999-15 April 2000

Delahoy, A.E. ; Bruns, J. ; Ruppert, A. ; Akhtar, M. ; Chen, L. ; Kiss, Z.J.

National Renewable Energy Laboratory (U.S.)

关键词: Back Contact;    36 Materials Science;    Efficiency;    Deposition;    Manufacturing;   

DOI  :  10.2172/763520
RP-ID  :  NREL/SR-520-28786
RP-ID  :  AC36-99GO10337
RP-ID  :  763520

美国|英语

来源: UNT Digital Library

【 摘 要 】

A summary of Energy Photovoltaics' Phase II work includes the following: (1) EPV has demonstrated that it can sputter a Mo back-contact capable of supporting very high efficiency cell processing. Using EPV Mo, NREL has deposited a 17.1% CIGS cell (no AR coating). EPV believes it can identify the signature of ``good'' Mo. The Mo was produced on EPV's 0.43 m{sup 2} pilot-line equipment; (2) EPV has performed compound synthesis for several classes of materials, namely non-Cu precursor materials, Cu-containing materials, and ternary buffer materials. Using a ternary compound synthesized at EPV (ZIS) as an evaporation source material for the buffer layer, a Cd-free CIGS device has been produced having an efficiency of 11.5% (560 mV, 32.1 mA/cm{sup 2}, FF 64.3%). The ZIS films are photoconductive, and the devices exhibit no dark-light crossover or light soaking effects; (3) EPV initiated the interest of the University of Oregon in capacitance spectroscopy of CIGS devices. An Urbach tail with characteristic energy E0 < 20meV was identified by transient photocapacitance spectroscopy; (4) Small-area CIGS devices were produced in the pilot-line system with an efficiency of 12.0% (581 mV, 30.1 mA/cm{sup 2}, FF 68.7%), and in an R and D-scale system with 13.3% efficiency (569 mV, 34.1 mA/cm{sup 2}, FF 68.1%); (5) An improved linear evaporation source for Cu delivery has been developed and was used for CIGS formation in the pilot-line system. The deposition width is 45 cm. This technological ``tour de force'' allows EPV to build large-area CIGS systems possessing considerable flexibility. In particular, both EPV's FORNAX process and NREL's 3-stage process have been implemented on the pilot line. A CIGS thickness uniformity of 7% over a 40 cm width has been achieved; (6) A 4-head linear source assembly was designed, constructed, and is in use. Flux monitoring is practiced; (7) Large-area CIGS modules were produced with Voc's up to 36.3 V; (8) EPV has started to construct an entirely new CIGS pilot line for scale-up and limited manufacturing purposes. The coating width will be 65 cm; (9) The company's analytical capabilities are currently being upgraded with the installation of ICP and SEM/EDS facilities.