Electrodeposition of In‐Se, Cu‐Se, and Cu‐In‐Se Thin Films

Abstract

Indium-selenium, copper-selenium, and copper-indium-selenium thin films have been prepared by electrodeposition techniques on molybdenum substrates. Electrodeposited precursors are prepared at varying potentials, pH, and deposition times. The adhesion and imiformity of indium selenide on molybdenum substrates are improved by electrodepositing an initial copper layer (500 A) on molybdenum. The films (In-Se, Cu-Se, and Cu-In-Se) are annealed at 250 and 450°C in Ar for 15 niln and are slow-cooled (3°C/mm). The films are characterized by electron microprobe analysis, inductivecoupled plasma spectrometry, x-ray diffraction analysis, Auger electron spectroscopy, and scanning electron microscopy. The as-deposited precursor films are loaded in a physical evaporation chamber and additional In or Cu and Se are added to the film to adjust the final composition to CuInSe2. The device fabricated using electrodeposited Cu-In-Se precursor layers resulted in a solar cell efficiency of 9.4%.

Electrochemically Fabricated Alloys and Semiconductors Containing Indium

“…InSe thin films were deposited from acidic aqueous solutions containing In 3+ and SeO 2 (or H 2 SeO 3 ) at potentials that ranged from −0.8 to −1.35 V vs. SCE [49][50][51][52][53][54][55] . The indium ions were from chloride 49,50,54,55) or sulfate [51][52][53] salts. In the deposition of InSe, the pH of the bath solution was below 1.7, 49,50,52,54,55) 2.4, 53) or 3.45.…”

“…The indium ions were from chloride 49,50,54,55) or sulfate [51][52][53] salts. In the deposition of InSe, the pH of the bath solution was below 1.7, 49,50,52,54,55) 2.4, 53) or 3.45. 51) Kampmann et al 53) performed the electrodeposition of InSe on an ITO substrate at −1.1 V vs. MSE and at 80 o C. Massaccesi et al 51) prepared In 2 Se 3 films on tin oxide substrates at 22 o C and 82 o C. Using XRD measurement, they observed that In 2 Se 3 films prepared at 82 o C had a better crystallinity than those obtained at 22 o C.…”

“…Many researchers have studied the effects of applied potentials or currents. Bhattacharya et al 52) analyzed InSe films using EPMA (electron microprobe analysis). Their results showed that InSe-deposited films obtained at −0.9 V vs. SCE were In 1.80 Se 3 and that the InSe films at −1.1 V were In 1.92 Se 3 .…”

“…Bhattacharya et at. 52) obtained electron microprobe analysis (EMPA) data of as-deposited CuInSe layers prepared at different potentials. At potentials of −0.5, −0.55, −0.6, and −0.65 V vs. SCE, the film compositi ons we re C u 1 .…”

Structural study of Cu2−x Se alloys produced by mechanical alloying

“…A solar cell (Schottky type) employing a semi-transparent layer of Cu 2Àx Se as the window material on an n-type semiconductor is estimated to have excellent photovoltaic properties and a conversion ef®ciency of around 9% (Okimura et al, 1980). Many preparation methods of Cu 2Àx Se alloys have been reported, including sonochemical synthesis (Xu et al, 2002;Xie et al, 2002), chemical bath deposition (Garcia et al, 1999;Clement et al, 1997;Pathan et al, 2003), the photochemical route (Yan et al, 2003), -irradiation (Qiao et al, 2000), solid-state reaction (Danilkin et al, 2003), microwave-assisted heating (Zhu et al, 2000), a hydrothermal method (Wang et al, 1999), electrodeposition (Lippkow & Strehblow, 1998;Battacharya et al, 1996) and mechanical alloying (MA; Ohtani et al, 1995).…”