Microwave assisted synthesis, characterization and thermoelectric properties of nanocrystalline copper antimony selenide thin films

Abstract

In the present work, we have synthesized p-type copper antimony selenide (Cu 3 SbSe 4 ) thin films in an aqueous alkaline medium using a microwave assisted synthesis technique. The deposited thin films were characterized by UV-Vis-NIR spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM) and thermoelectric techniques. On the basis of experimental results, a possible reaction mechanism has been discussed in detail. The band gap of the as deposited film is 1.94 eV and after annealing it reaches 1.87 eV for Cu 3 SbSe 4 . XRD results indicate that the as deposited thin films of CuSbSe 2 have an orthorhombic crystal structure with secondary mixed phases and after annealing this is converted to Cu 3 SbSe 4 having a pure tetragonal crystal structure. FESEM micrographs of Cu 3 SbSe 4 showed a spherically diffused granular morphology having an average grain size of 25 nm. The HRTEM result of Cu 3 SbSe 4 shows good crystallinity with a lattice spacing of 0.327 nm along the (112) plane. The EDS spectrum shows the presence of Cu, Sb and Se elements. The thermoelectric figure of merit (ZT) of the as deposited film is calculated to be 0.059 at 300 K and that of annealed Cu 3 SbSe 4 is found to be 0.141 at 300 K.

Thermoelectric properties of nanocrystalline Cu3SbSe4 thin films deposited by a self-organized arrested precipitation technique

“…The nature of plot suggests the direct allowed type of transition The value of Eg was obtained by extrapolating linear portion of plot and taking the intercept on the X-axis of (αhν) 2 reported value [31]. Figure 3 shows the indexed XRD patterns of as deposited and annealed thin film with standard diffraction pattern in range of 20° to 80°.…”

“…In the typical experiment, 40 copper sulphate pentahydrate (CuSO 4 ·5H 2 O, 99.5 % Ranbaxy), antimony trichloride (SbCl 3 , 99.0 % Merck) were used as a source of Cu and Sb ions with tartaric acid (C 4 H 6 O 6 , 99.0 % S D Fine Chem) as a complexing agent. Aqueous sodium selenosulphite (Na 2 SeSO 3 ) solution was used as source of Se, 45 which was obtained by refluxing selenium metal powder (Se, 99.5 % Sigma Aldrich) with saturated solution of sodium sulphite (Na 2 SO 3 , 97.0 % S D Fine Chem) as per our earlier report [31]. Ammonia (NH 3 , 28.0-30.0 % Thomas Baker) was used to adjust the pH of the reaction bath and ammonium acetate (C 2 H 4 O 2 ·NH 3 , 50 96.0 % S D Fine Chem) was used as buffer solution.…”

“…Last year Tyagi et al [27][28] and Wei et al [29][30] have reported mechanical fusion, followed by spark plasma sintering method for synthesis of this material. Also last year we have reported microwave assisted synthesis technique for deposition of Cu 3 SbSe 4 thin films [31]. However, these methods require high temperature and time 5 consuming manufacturing processes.…”

Thermoelectric Properties of Indium(III)‐Doped Copper Antimony Selenide Thin Films Deposited Using a Microwave‐Assisted Technique

“…In III ‐doped Cu 3 SbSe 4 thin films were synthesised by using a reported method with slight modifications . It involves a one‐pot solution‐phase reaction between copper sulfate pentahydrate, antimony tartrate, anhydrous indium sulfate and sodium selenosulfite, freshly heated to refluxed.…”

“…Cu‐Sb‐Se is a very efficient and capable optoelectronic material . It has been prepared by several methods such as direct fusion, solid‐state reaction, electrodeposition, spark plasma method, solvothermal method, co‐precipitation, rapid injection, hot injection and microwave‐assisted method . The microwave‐assisted technique is a promising method for the synthesis of nanocrystalline metal chalcogenide thin films.…”