Microwave‐assisted synthesis of CuInSe₂ nanoparticles in low‐absorbing solvents

Abstract

Copper indium diselenide (CIS) nanoparticles were synthesized using a microwave‐assisted one‐pot solvothermal approach. For these studies high microwave‐absorbing precursors were used in combination with low microwave absorbing solvents tri‐n‐octylphosphine (TOP) and oleic acid (OA) to investigate the effect of selective heating of the precursors on nanoparticle synthesis. High‐resolution transmission electron microscopy (TEM) results indicated that the nanoparticles were spherical, crystalline and 4–5 nm in diameter. X‐ray diffraction (XRD) results indicated that the nanoparticles had a body‐centered tetragonal structure with planar defects that decreased in concentration with increasing reaction temperature and reaction time. The nanoparticle compositions varied depending on the reaction conditions and the compositions were found to approach stoichiometry for increased reaction times. Fourier transform infrared (FTIR) spectroscopy indicated both solvents adsorbed to the nanoparticle surface and energy dispersive spectroscopy indicated that these ligands became chlorinated during the reaction. The uniform temperature profile offered by the microwave heating allowed for highly reproducible batch‐to‐batch reactions, allowing for tight control over composition and defect concentration.

Gas–liquid segmented flow microwave-assisted synthesis of MOF-74(Ni) under moderate pressures

“…51 Compared to conventional heating, microwave heating is an excellent approach for initiating nucleation because of the rapid heating rates and uniform volumetric heating which lead to instantaneous nucleation, homogeneous growth, and high reproducibility of reactions. 52,53 Microwave heating can lead to the uniform formation of particles under milder temperature and pressure, with reaction times in minutes as opposed to hours or days. Excellent control over nanoparticle size with very narrow size distributions has been shown for reactions using microwave heating.…”

Ionothermal Syntheses of Nano- and Microstructured Ternary Copper–Indium–Chalcogenides

“…One of the first reports on the production of CIS quantum dots was in 1999 using a hot-injection technique with trioctylphosphine selenide (TOPSe) as the selenium precursor along with trioctylphosphine oxide (TOPO) . Other reports on the synthesis of CIS using trioctylphosphine (TOP) and/or dioctylphosphine oxide (DOPO) as nonpolar solvents have also been published, , with amines also extensively utilized. ,− These additives have been implemented as structure-directing agents, capping agents, and solvents in the preparation of CuInSe 2 . High-temperature methods have been reported such as a sintering method, , sputtering selenization, , and hydrothermal selenization in the formation of CIS.…”

Aluminum doping of CuInSe2 synthesized by solution process and its effect on structure, morphology, and bandgap tuning

“…Copper indium selenium (CuInSe 2 ) is a I–III–VI 2 semiconductor and is expected to be a promising material for solar cells absorber layer due to its low cost, high absorption coefficient, excellent optical and electrical properties . As a direct‐bandgap semiconductor, the chalcopyrite CuInSe 2 system has high efficiency to achieve sufficient light absorption and has a remarkable tolerance for structural defects as absorber materials . It is unnecessary for strict requirements on high level material quality, and generally reduces processing costs compared with crystalline silicon solar cells .…”

“…CuInSe 2 is usually doped with Ga or S to improve its bandgap and efficiency. The efficiency of solar cells with a Cu(In,Ga)Se 2 absorption layer has been achieved on the laboratory scale at 20.8% .…”

“…It is unnecessary for strict requirements on high level material quality, and generally reduces processing costs compared with crystalline silicon solar cells [4]. CuInSe 2 is usually doped with Ga or S [3,[5][6][7] to improve its bandgap and efficiency. The efficiency of solar cells with a Cu(In,Ga)Se 2 absorption layer has been achieved on the laboratory scale at 20.8% [7].…”