Synthesis of CuIn<I><SUB>1-x</SUB></I>Ga<I><SUB>x</SUB></I>Se<SUB>2</SUB> Nanoparticles by Thermal Decomposition Method with Tunable Ga Content

Abstract

Chalcopyrite Culn(1-x)Ga(x)Se2 (CIGS) nanoparticles were synthesized by mixing copper (I) chloride (CuCl), Indium (III) chloride (InCl3), gallium (III) chloride (GaCl3) and selenium (Se) in oleylamine (OLA) at 260 degrees C for 4 h under nitrogen atmosphere. The Ga/(In+ Ga) ratio was tuned across the entire stoichiometric range from 0 to 1. X-ray diffraction analysis (XRD) revealed chalcopyrite crystal structure for samples prepared with x = 0, 0.3, 0.5, 0.7 and 1. The lattice parameters a and c decreased linearly with increasing Ga concentration which is consistent with Vegard's law. Raman spectra exhibited A, optical phonon vibrational mode for synthesized nanoparticles which gradually shifted to higher wavenumber with increasing Ga content. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) images showed irregular as well as hexagonal plate like morphologies in the size range of 100 to 400 nm. High-resolution transmission electron microscopy (HR-TEM) images showed well-defined lattice fringes and d-spacing correspond to (112) plane which gradually decreases with increasing Ga content. The material compositions of synthesized CIGS nanoparticles with x = 0, 0.3, 0.5, 0.7 and 1 were very close to the desired stoichiometry which was confirmed by energy dispersive X-ray analysis (EDAX). Ultraviolet visible near infrared (UV-VIS-NIR) absorption spectra of the synthesized CIGS nanoparticles revealed that the bandgap could be tuned over the range 1 to 1.7 eV by varying the Ga/(In+Ga) ratio.

Synthesis and Characterization of CuIn1−xGaxSe2 Semiconductor Nanocrystals

“…The uncertainty of these values was about 0.01 eV. These values agree with those reported in other papers [ 4 , 21 ].…”

“…There are various methods for manufacturing CuIn 1− x Ga x Se 2 nanocrystals, such as hot injection synthesis [ 5 , 18 ], the solvothermal route [ 4 ], thermal decomposition [ 19 , 20 , 21 ], the modified polyol route [ 22 ], and the mechanochemical process [ 23 ]. Cui and co-workers synthesized CuIn 1− x Ga x Se 2 nanocrystals by heating metal chlorides in a selenium solution containing oleylamine and glycerol [ 24 ].…”

Unveiling the impact of Cu content on the physical properties and photovoltaic performance of solution‐processed Cu(In,Ga)Se2solar cell absorber

“…Figure 1B shows the Raman spectra of CIGSe at different CGI values which were normalized to the prominent peak intensity (A 1 mode). All the samples showed a dominant A 1 optical phonon mode, which denotes the vibration of Se anions in x – y plane while cations of Cu, In, and Ga are being at rest 2 . As CGI value decreases, A 1 mode peak is getting wide which in turn increases the FWHM that reveals the reduction in the crystallinity of CIGSe as noticed by Raquel Caballero et al 18 Besides, as CGI value decreases, the A 1 mode peak position shifted steadily toward higher wavenumber (blue shift) from 174.44 to 180.26 cm −1 that could be due to the lattice compression in the unit cell when the Cu content reduces, which is consistent with the literature 14 .…”

“…Cu(In,Ga)Se 2 (CIGSe) compound semiconductor has gained tremendous attention as the most promising light‐absorbing material in thin‐film photovoltaic devices for efficient solar energy conversion. Besides, CIGSe possesses excellent electrical and optoelectronic properties such as direct bandgap, high optical absorption coefficient, tunable bandgap, high quantum efficiency, radiation hardness, and long‐term excitation stability 1‐4 . To date, CIG(S,Se) 2 thin‐film solar cell has demonstrated record efficiency as high as 23.35% 5 .…”

Syntheses and Characterizations of CuIn1-xZnxSe2 Chalcopyrite Nanoparticles

“…Therefore, the band gap of these compounds increases [31]. All these results show that the role of zinc is identical to that of aluminum in Cu (In, Al) Se 2 powders [32,33] as well as gallium in Cu (In, Ga) Se 2 powders [11,31,34,35]. In the latter case, Zn is cheaper than Ga concerning the ease of acquisition because it is a natural component of the Earth's crust and is an integral part of our environment, while Ga is a rare chemical element.…”