RF-magnetron sputtered kesterite Cu2ZnSnS4 thin film using single quaternary sputtering target prepared by sintering process.
Cu2ZnSnS4 (CZTS) thin film applicable to an absorber material in compound thin film solar cells was deposited by a single quaternary sputtering target containing four components--Cu, Zn, Sn, and S-and its material properties were investigated. A single quaternary sputtering target was fabricated by sequential powder mixing/ball milling, pressure moulding, and a sintering process. An as-fabricated pellet or sputter target sintered at 500 degrees C-700 degrees C showed relevant peaks associated with CZTS phases. However, acceptable density as a sputter target (> 90% of ideal density) was attained up to a sintering temperature of only 500 degrees C due to thermal expansion. Unlike other metallic precursor approaches, there was no volume expansion after sulfurization. The sulfurized CZTS film contained CZTS phases including some secondary phases such as SnS or SnS2 depending on the film thickness. This result was attributed to the different sputtering yields of the constituents in the sputter target. Optical E(g) decreased with increasing deposition time. The E(g) attained was 1.488 eV, well-matched to the reported CZTS data. The carrier concentration, resistivity, and mobility of the CZTS film were 1.29 x 10(17) cm(-3), 1.2 x 10(-1) omega x cm and 5.44 cm(-3) N x sec, respectively, showing suitability for absorber layer applications.
Division of Materials Science and Engineering, Hanyang University, Seoul 133-791, Korea.
Dongjun
D
Yoo
Moonsuk
M
Choi
Seung Chan
SC
Heo
Dohyung
D
Kim
Chulwon
C
Chung
Changhwan
C
Choi
D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D011211:Electric Power Supplies; D006361:Heating / Q000379:methods; D047348:Hydrolyzable Tannins / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D010316:Particle Size; D011846:Radio Waves; D012993:Solar Energy; D013499:Surface Properties; D019287:Zinc Sulfate / Q000737:chemistry*
D047348:Hydrolyzable Tannins; D046911:Macromolecular Substances; D008567:Membranes, Artificial; C036335:kastrin; D019287:Zinc Sulfate; D003300:Copper