Preparation of CuInGaSe 2 Absorber Layer by Nanoparticles-Based Spray Deposition
- PDF / 482,159 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 19 Downloads / 224 Views
L5.10.1
Preparation of CuInGaSe2 Absorber Layer by Nanoparticles-Based Spray Deposition Ki-Hyun Kim1,2, Young-Gab Chun1, Byung-Ok Park2 and Kyung-Hoon Yoon*1 1 Solar Cells Research Center, Korea Institute of Energy Research, 71-2 Jang-dong, Yusong-gu, Daejeon, 305-343, Republic of Korea * Tel: +82-42-860-3191/ Fax: +82-42-860-3739/ E-mail: [email protected] 2 Dept. of Inorganic Materials Engineering, Kyungpook National University, 1370 Sankyuk-dong, Puk-ku, Daegu, 702-701, Republic of Korea ABSTRACT CIGS nanoparticles for the CIGS absorber layer have been synthesized by low temperature colloidal routes. The CIGS absorber layers for solar cells have been prepared by spray deposition of CIGS nanoparticle precursors (~20 nm) in glove box under inert atmosphere. An automatic air atomizing nozzle spray system with computer controlled X-Y step motor system was used to spray. The nanoparticle precursor CIGS film was deposited onto molybdenum-coated soda-lime glass substrates (2.5 ㎝ Х 5.0 ㎝) heated to 160℃. The film thickness in the range of 2 ㎛ ± 0.3 ㎛ was attained by spraying of 3 mM colloidal over an area of 12.5 ㎠. The coalescence between particles was observed in the CIGS absorber layer under post-treatment of over 550℃. This is related to the reactive sintering among the nanoparticles to reduce surface energy of the particles. The CuxSe thin film, formed on Mo film by evaporation, improved adhesion between CIGS and Mo layers and enhanced the coalescence of the particles in the CIGS layer. These are closely related to the fluxing of Cu2Se phase which has relatively low melting temperature. The CdS buffer layer was deposited on the CIGS/Mo/soda-lime glass substrate by chemical bath deposition. The CIGS nanoparticles-based absorber layers were characterized by using energy dispersive spectroscopy (EDS), x-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM). INTRODUCTION Compound solar cell devices consist of electrode/transparent conducting oxides (TCO)/buffer layer/absorber layer/back contact/soda-lime glass. In general, chalcopyrite material of CuInGaSe2 (CIGS) is known to be a very prominent absorber layer for high efficiency thin film solar cell devices. Recently, improved efficiencies for CdS/Cu(InGa)Se2 (Eg~1.1 eV) solar cells have been reported with a value of 19.2% [1,2]. While this CIGS device possesses the highest thin film polycrystalline solar cell efficiency to date, the scaling of this technology toward commercialization presents many challenges. Amongst various physical and chemical deposition techniques of preparing thin semiconducting film, the spray deposition is a simple, easy, and
L5.10.2
economical technique with the unique feature to control the preparative parameters, especially by controlling the substrate temperature. In this work, we have tried a novel approach to fabricate CIGS solar cells in which a nonvacuum process is used for depositing the CIGS absorber layer. With the CIGS nanoparticles (~20 nm) synthesized by colloidal route, we prepared and analyzed the CIGS
Data Loading...
