Preparation Of CuInSe2 Thin Films Research Articles

On the preparation of CuInSe2 thin films via two‒stage selenization

A two-stage selenization method for preparing CuInSe2 thin films in a carrier-gas (nitrogen) flow is developed. The dependences between the morphology and structure of CuInSe2 thin films and the selenization temperature are studied via electron microscopy and X-ray diffraction analysis. It is demonstrated that the film incorporates copper and indium selenides in the temperature range 300°C ≤ T < 400°C and a stoichiometric film with ordered chalcopyrite is formed at Т = 400°С. The possible mechanism whereby a CuInSe2 thin film is generated with the participation of selenization centers, namely, Cu2Se and In2Se3 grains, is discussed.

Preparation of CuInSe2 thin films by selenization of co-sputtered Cu-In precursors using rapid thermal processing

CuInSe2 thin films have been synthesized by selenization of co-sputtered Cu-In precursors using rapid thermal processing (RTP). Heat treatments from 400 to 450 °C for periods between 1 min and 10 min were carried out on (Cu-In)/Se precursors. Phase evolution as function of reaction temperature and holding time was analyzed according to XRD and SEM results. Severe Se loss during RTP was proved in our experiments and has been reported by many other researchers. To solve the problem, a new effective way of reducing Se loss was presented, which is based on low temperature heat treatment at 250 °C before high temperature annealing. Nearly single-phase CuInSe2 thin films have been achieved by annealing precursors at 250 °C for 5 min then 450 °C for 1 min. Se loss can be significantly reduced via low temperature heat treatment by the fact that under 250 °C, Se is evaporated mildly and largely consumed as Cu-Se and In-Se binary selenides.

Preparation of CuInSe2 thin films through metal organic chemical vapor deposition method by using di-μ-methylselenobis(dimethylindium) and bis(ethylisobutyrylacetato) copper(II) precursors

Highly polycrystalline copper indium diselenide (CuInSe2) thin films on molybdenum substrate were successfully grown at 330 °C through two-stage metal organic chemical vapor deposition (MOCVD) method by using two precursors at relatively mild conditions. First, phase pure InSe thin film was prepared on molybdenum substrate by using a single-source precursor, di-μ-methylselenobis(dimethylindium). Second, on this InSe/Mo film, bis(ethylisobutyrylacetato) copper(II) designated as Cu(eiac)2 was treated by MOCVD to produce CuInSe2 films. The thickness and stoichiometry of the product films were found to be easily controlled in this method by adjusting the process conditions. Also, there were no appreciable amounts of carbon and oxygen impurities in the prepared copper indium diselenide films.

Preparation of CuInSe2 thin films by selenization of co-sputtered Cu–In precursors

CuInSe2 thin films have been prepared by high Se vapor selenization of co-sputtered Cu–In alloy precursors within a partially closed graphite container. Cu–In alloys with different compositions were investigated. X-ray diffraction (XRD) analysis of the films showed mainly CuIn2 and Cu11In9 phases and the Cu11In9 peak intensity was found to increase as the alloy composition tended towards Cu-rich. A linear dependence of the alloy composition on the Cu/In deposition power was observed from energy dispersive analysis by X-rays (EDX). A three-fold volume expansion was exhibited by all the CuInSe2 films after selenization at 500–550 °C. Scanning electron microscopy (SEM) analysis of the films showed large and densely packed crystal structures with sizes above 5 μm. The CuInSe2 films exhibited single phase chalcopyrite structure with preferential orientation in the (1 1 2) direction. The EDX composition analyses of the films showed Cu/In ratio ranging from 0.43 to 1.2, and Se/(Cu+In) ratios from 0.92 to 1.47. The measured film resistivities varied from 10-1 to 105 Ωcm. The Cu–In alloy precursors with Cu/In ratio less than 0.70 were found to form CuIn3Se5 a defect chalcopyrite compound. All films were Se rich, with the exception of samples with very high Cu content.© 1998 Kluwer Academic Publishers

Preparation of CuInSe2 Thin Films by Chemical Spray Pyrolysis

CuInSe2 thin films have been prepared by chemical spray pyrolysis (CSP) on glass substrate from the ethanol aqueous solution containing CuCl2, InCl3 and N,N-dimethylselenourea. Properlies of the CuInSe2 films (electrical, structural, optical absorption and morphological properties) have been systematically studied in terms of substrate temperature (T s), pH and the ion ratio (Cu/In) of the spray solution. Good chalcopyrite CuInSe2 films with large grains have been grown using the neutralized spray solution (pH=4) at the growth temperature of 360° C. On the other hand, low values of T s, pH and Cu/In led to the production of sphalerite films.

移動帯域加熱法によるＣｕＩｎＳｅ２薄膜の作製

Application of travelling zone heater method to preparation of CuInSe2 thin films was studied. Conditions for preparing single phase CuInSe2 films grain sizes of up to 2μm are clarified.

Preparation of CuInSe2 thin films by selenization of CuInO precursors

Abstract Polycrystalline CuInSe2 films were prepared by selenization of CuInO films. CuInO precursor were prepared from Cu2In2O5 target by rf-magnetron sputtering and pulsed laser deposition. The CuInO films were converted into CuInSe2 films by annealing in H2Se gas atmosphere. The CuInSe2 films obtained by selenizing CuInO films prepared by a pulsed laser deposition, contained an impurity phase such as In2O3. But singlephase chalcopyrite CuInSe2 films were obtained by selenizing the near stoichiometric CuInO film prepared by a rf-magnetron sputtering at a temperature of 450°C.

Studies on CuIn precursor for the preparation of CuInSe2 thin films by the selenization technique

Abstract The effect of temperature on the degree of alloy formation between Cu and In layers has been studied for the preparation of CuInSe 2 films by the selenization technique. The mechanism of alloy formation is different in bilayers annealed at temperatures lower and higher than the melting point of In, or prepared by deposition of Cu and In at 200°C and 150°C, respectively. While the annealing of the precursor up to 200°C produces an alloy in the interface region of Cu and In layers, annealing at 500°C completely changes its morphology. The effect of alloy formation in the precursor on the selenized CuInSe 2 films is studied using structural, morphological, optical and compositional properties.

CuInSe2 Thin Film Prepared by Evaporation of Cu2Se and In2Se3

Preparation of CuInSe2 thin films by evaporation of In2Se3 and Cu2Se is proposed. Sequential evaporation of In2Se3 and Cu2Se is superior in controlling composition of films and the p-type film with 24 cm2/V·s in Hall mobility is obtained. By heating substrates during deposition and using rf plasma, we have succeeded in obtaining the <112> highly oriented CuInSe2 thin films.