Under magnetic stirring, 90 mmol of 2,4-pentanedione (9 ml) was added and kept stirred for another 15 min. Then Sn(acac)4 was precipitated by the addition of triethylamine (6 ml). The resulting Sn(acac)4 was washed for several times by ethanol and water, then dried in the vacuum. A typical synthetic procedure of CTZSe NCs is

briefly described as follows: 1 ml OLA, 1 ml DT, and 2 mmol Se powder were placed in a three-neck flask and stirred to dissolve the Se powder. Once the Se powder was completely dissolved, 0.5 mmol Cu(acac)2, 0.25 mmol Zn(acac)2, 0.25 mmol Sn(acac)4, 1 ml DT, and 10 ml OLA were added under vigorous stirring. Sapanisertib cell line Then the mixture was placed in an oil bath at 240°C and maintained for 0.5 h. After that, the flask was rapidly cooled to room temperature, and the as-synthesized NCs were separated by precipitation with ethanol and collected by centrifugation at 9,500 rpm for 4 min. The supernatant was decanted. The precipitates were dispersed in hexane and further purified by ethanol for several times. The precipitates were dried under vacuum at room temperature.

The ligand exchange process was carried out according to the literature with some modification [23]. Colloidal dispersion of CZTSe NCs with organic ligand was prepared in GDC 0032 in vitro toluene, while the solution of CZTSe NCs with inorganic ligand was prepared in polar formamide (FA) immiscible with toluene. For a typical ligand exchange, 20 mg CZTSe NCs was dispersed into 3 ml toluene and 0.1 ml (NH4)2S was dissolved into 3 ml FA. Then the (NH4)2S solution in FA was mixed with the CZTSe NC dispersion in toluene. The mixture was stirred for about 10 min leading to a complete phase transfer of CZTSe NCs from toluene to the FA phase. The phase transfer can be easily monitored by the color change of toluene (black to colorless) and FA (yellow to black) phases. The FA phase was separated out followed by triple washing with toluene to remove Bumetanide any remaining nonpolar organic species. The morphology of CZTSe NCs was characterized

by transmission electron microscopy (TEM; JSM-2010, JEOL Ltd., Akishima-shi, Japan). The phase and crystallographic structure of the products were identified by X-ray diffraction (XRD; X’Pert Pro, Philips, Amsterdam, The Netherlands). The UV-visible (UV-vis) absorption spectra were obtained by using a UV-vis Palbociclib clinical trial spectrometer (Lambda 35, PerkinElmer, Waltham, MA, USA). Fourier transform infrared (FTIR) spectra were recorded on a Nicolet 360 FTIR spectrometer (Thermo Fisher Scientific, Inc., Waltham, MA, USA) using KBr pellets in the range of 4,000 of 400 cm−1. The Raman spectrum was recorded using a LABRAM-1B confocal laser micro-Raman spectrometer (HORIBA, Kyoto, Japan) with the wavelength of 632.8 nm. The resistivity was tested by the four-probe method on a digital source meter (Keithley 2400, Keithley Instruments, Inc., Cleveland, OH, USA).