Characterization of Cu2ZnSnSe4 (CZTSe) nanoparticles synthesized via solvothermal method for solar cell applications

Abstract

Stannite Cu 2 ZnSnSe 4 (CZTSe) nanoparticles were synthesized using a simple solvothermal process at low temperatures using ethylenediamine as a solvent. The structures and morphologies of CZTSe nanoparticles were characterized as functions of various zinc salts in the precursors. Nanosized CZTSe particles, formed with zinc chloride as the source of zinc and obtained at 240°C after 30 min of the aforementioned process, exhibited a single CZTSe phase. Increasing the processing duration to 6 h markedly increased the crystallinity of heat treated powders. All particles that were obtained after 6 h 240°C from various zinc salts exhibited a single tetragonal phase with particle sizes in the range of 30-60 nm. CZTSe nanoparticles that were obtained from zinc chloride and zinc acetylacetonate had better crystallinity compared to particles obtained from other zinc salts. The structural variation in CZTSe that was synthesized from zinc chloride was observed as a function of Cu/(Zn ? Sn) ratio. A Cu poor and Zn rich conditions resulted into a highly crystalline CZTSe phase with relatively smooth and closely packed morphology. The CZTSe nanoparticles, obtained from ZnCl 2 , were evaluated for potential use in solar cells via preparing precursor ink. The contents of the precursor ink were fixed to Cu/(Zn ? Sn) = 0.8 and Zn/Sn = 1.2, and the ink was coated onto Mo substrates via drop casting. The GIXRD patterns of the film showed single CZTSe phase without any binary phases throughout the film. These results demonstrated that the as formed CZTSe nanoparticles are suitable for use as absorber layers in lowcost solar cells.

Effect of Different Selenium Precursors on Structural Characteristics and Chemical Composition of Cu2ZnSnSe4 Nanocrystals

“…In such way in the research work [43] [46][47][48]. Using precursors based on cheaper elemental selenium Cu 2 ZnSnSe 4 , NCs were obtained only by the solvothermal method [49,50], hydrothermal method [51], two-step hot-injection method [52][53], and solventthermal re ux technique [54][55].…”

Synthesis of Cu 2 ZnSnSe 4 thin‐film solar cells from nanoparticles by a non‐vacuum mechanical ball milling and rapid thermal processing

“…The nanoparticle inks deposition methods involve depositing nanoparticles inks and then selenisation in H 2 Se or Se vapour [23]. The CZTSe nanoparticles were often synthesised by hot injection methods or solvothermal methods, which require complicated Schlenk‐line reaction vessel and intricate post‐processing [19, 24]. The hydrazine‐based inks processing is an attractive way to the synthesis of carbon‐free CZTSSe thin films.…”

Aqueous Synthesis of High-Quality Cu2ZnSnS4 Nanocrystals and Their Thermal Annealing Characteristics

“…Quaternary I 2 -II-IV-VI 4 compound copper zinc tin sulfide (CZTS) is regarded as a promising photovoltaic material due to its excellent optoelectronic properties, tunable band gap, and earth-abundant elemental composition . Various methods have been reported for the deposition of CZTS thin films, including the decomposition of molten salts, , reactive sputtering, , electroplating, , vapor deposition, , precursor solution deposition, − and nanoparticle ink sintering. − Of these methods, the approach using CZTS nanoparticle inks is one of the most promising, commonly achieving efficiencies over 8.5%, ,− with the highest-efficiency nanoparticle-based CZTS solar cells reported to date (11.1%) being fabricated using a hydrazine-based synthesis route . This success is largely due to the better phase and compositional control achieved through solution processing, compared to the alternative synthesis approaches.…”

“…However, synthesis routes for the production of high-quality CZTS nanoparticles typically involve the use of toxic solvents and extensive postsynthesis processing to remove organic impurities. − ,,− , These are clearly undesirable when considering that reproducibility and scale-up are essential for commercial production, which requires the minimization of hazards and additional processing steps. While existing “greener” CZTS nanoparticle syntheses based on water and ethanol dispersions overcome the risks associated with using toxic hydrazine, ,,− ,, eliminating organic contaminants, which are usually present as an excess of aliphatic ligands used to achieve homogeneous dispersions of nanocrystals, remains a challenge.…”