Chris Eberspacher

CuInSe/sub 2/ cells and modules

Recent CuInSe/sub 2/ photovoltaic technology advances are discussed. 14.1% active area efficient test cells and the fabrication of monolithic integrated modules with power outputs of 112 W/m/sup 2/ on 940 cm/sup 2/ and 91.4 W/m/sup 2/ on 3900 cm/sup 2/ have been achieved. Packaged modules are stable outdoors. Studies indicate a recombination controlled junction mechanism and imply a wide CIS compositional range over which high-efficiency junctions are possible. Processing improvements already demonstrated on test cells and 940 cm/sup 2/ modules will yield 52-W, 3900-cm/sup 2/ CIS modules. >

Single and tandem junction CuInSe/sub 2/ cell and module technology

A ZnO/thin CdS/CuInSe/sub 2/ (CIS) cell and a 10.5 W, 938 cm/sup 2/ 55-cell CIS module with a 11.2% aperture area efficiency are reported. Other devices include 10% efficient ZnO/thin ZnSe/CIS and 7.3% efficient ZnO/thin CdS/CuInS/sub 2/ cells. A four-terminal 15.6% efficient semitransparent thin-film silicon:hydrogen alloy (TFS)/CIS tandem cell and a 12.3% aperture area efficient TFS/CIS module are also demonstrated. Insight into the factors affecting their performance is provided by modeling and analysis of modules and test structures.<<ETX>>

Non-vacuum Thin-film CIGS Modules

Non-vacuum techniques have been used to deposit coatings of copper indium gallium selenide (CIGS) and metal oxide transparent conductors useful for fabricating thin-film photovoltaic modules. Coatings are formed from nanoparticulate precursor materials using spraying, printing and spin-coating methods. Sprayed layers exhibit non-planar morphologies and low particle packing, and CIGS films made from sprayed precursor layers exhibit related non-planar morphologies and residual void space. The surface roughness of spray-derived CIGS films reduces the sheet conductance of overlying coatings; thin coatings of transparent conductors deposited on rough CIGS films exhibit sheet resistances up to two orders of magnitude higher than equivalent coatings on planar surfaces. Slurry additives can improve layer morphology and sintered film properties, but organic additives can leave carbon contamination of the sintered CIGS films. The fabrication of multi-cell modules imposes additional constraints on transparent conductor sheet conductance.