硒化镉(CdSe)量子点具有荧光量子产率高、稳定性好以及光谱易于调节等优点,在发光二极管、太阳能电池及荧光标记等领域有着广阔的应用前景,而研究不同工艺条件对其性能的影响具有重要意义.以金属氯化物为Cd和Se源,以巯基丙酸(3-MPA)为包覆剂利用水相回流反应法在100 ℃下反应120 min制备了系列CdSe量子点,并讨论了不同Cd与Se比例时样品的形貌、带隙及光学性能的变化.CdSe量子点的尺度在2.19~2.57 nm,最强激发峰位于431 nm,发射峰位于561 nm,吸收光谱带边从460 nm蓝移到450 nm,表明样品在合成过程中,Cd与Se比例对样品的性能有一定的影响.
Cadmium selenide(CdSe)quantum dots have the advantages of high fluorescence quantum yield, good stability and easy spectrum adjustment. They have broad application prospects in the fields of light-emitting diodes, solar cells and fluorescent labeling etc. It is of great significance to study the effects of different process conditions on their properties. Using mercaptopropionic acid(3-MPA)as coating agent, a series of CdSe quantum dots have been prepared by aqueous reflux reaction at 100 ℃ for 120 min. The changes of morphology, band gap and optical properties of the samples with different elemental ratio of Cd to Se are discussed. The size of CdSe quantum dots is about 2.19 nm to 2.57 nm. The strongest excitation peak locates at 431 nm, the emission peak is at 561 nm, and the absorption spectrum blueshifts from 460 nm to 450 nm, indicating that the elemental ratio of Cd to Se has great influence on the properties of CdSe quantum dots.
[1] AHAMED S T, KULSI C, KIRTI, et al. Synthesis of multifunctional CdSe and Pd quantum dot decorated CdSe thin films for photocatalytic, electrocatalytic and thermoelectric applications[J]. Surf Interfaces, 2021, 25:101149. DOI: 10.1016/j.surfin.2021.101149.
[2] MARANDI M, MIRAHMADI F S. Aqueous synthesis of CdTe-CdS core shell nanocrystals and effect of shellformation process on the efficiency of quantum dot sensitized solar cells[J]. Sol Energy, 2019, 188:35-44. DOI: 10.1016/j.solener.2019.05.070.
[3] KATARI J E B, COLVIN V L, ALIVISATORS A P. X-ray photoelectron-spectroscopy of CdSe nanocrystals with applications to studies of the nanocrystal surface[J]. J Phys Chem, 1994, 98:4109-4117. DOI: 10.1021/j100066a034.
[4] KUNO M. Tailoring the inherent optical and electrical properties of nanostructures[J]. J Phys Chem Lett, 2014, 5: 3817-3818. DOI: 10.1021/jz502041a.
[5] EFROS A L, ROSEN M, KUNO M, et al. Band-edge exciton in quantum dots of semi-conductors with a degenerate valence band: Dark and bright exciton states[J]. Phys Rev B, 1996, 54(7): 4843-4856. DOI: 10.1103/PhysRevB.54.4843.
[6] ÜNLÜ C. CsPbX3 Controlling defect state emission in ultra-small sized tellurium doped CdSe nanocrystals via two-phase synthesis method[J]. Opt Mater, 2019, 89:361-367. DOI: 10.1016/j.optmat.2019.01.050.
[7] HANDIQUE K C, SIBOH D, NANUNG Y, et al. Effect of temperature on the optical properties of chemically synthesized CdSe nanostructures[J]. Mater Today: Proceedings, 2021, 46(14):6312-6317. DOI: 10.1016/j.matpr.2020.05.444.
[8] DLAMINI N N, RAJASEKHAR PULLABHOTLA V S R, REVAPRASADU N. Synthesis of triethanolamine(TEA)capped CdSe nanoparticles[J]. Mater Lett, 2011, 65:1283-1286. DOI: 10.1016/j.matlet.2011.01.050.
[9] EMARA M M, GREGORY VAN PATTEN P. Effect of oxygen and polymer matrix on photo-induced changes in CdSe quantum dots[J]. Mater Chem Phys, 2020, 256:123652. DOI: 10.1016/j.matchemphys.2020.123652.
[10] HONG H S, KIM M S, BYUN E K. Facile synthesis and characterization of zinc selenide nanoparticles in aqueous solution at room temperature[J]. J Cryst Growth, 2020, 535:125523. DOI: 10.1016/j.jcrysgro.2020.125523.
[11] POKHRIYAL S, BISWAS S. Effects of structural parameters on the optical and magnetic properties of surface stabilized intrinsic CdSe nanoparticles[J]. Appl Surf Sci, 2020, 501:144040. DOI: 10.1016/j.apsusc.2019.144040.
[12] MRAD R, POGGI M, BRAHIM N B, et al. Tailoring the photophysical properties and excitonic radiative decay of soluble CdSe quantum dots by controling the ratio of capping thiol ligand[J]. Materialia, 2019, 5: 100191. DOI: 10.1016/j.mtla.2018.100191.
[13] MARANDI M, MIRAHMADI F S. Aqueous synthesis of the CdTe NCs and influence of size on photovoltaic performance of the CdS/CdTe co-sensitized solar cells[J]. J Alloy Compd, 2019, 800:140-149. DOI: 10.1016/j.jallcom.2019.06.025.
[14] BELLACANZONE C, TARPANI L, GENTILI P L, et al. Effeds of glutathione on the luminescent behavior of CdSe-nanocrystals[J]. J Lumin, 2020,226:117513. DOI: 10.1016/j.jlumin.2020.117513.
[15] YANG K, LUO G Z, ZENG X J, et al. Aqueous quantum dots with high fluorescence, colloidal stability and biocompatibility encapsulated by an amphiphilic fluorine copolymer[J]. Polymer, 2019, 179:121706. DOI: 10.1016/j.polymer.2019.121706.
[16] SONG X H, MA Z, LI L X, et al. Aqueous synthesis of alloyed CdSexTe1-x colloidal quantum dots and their insitu assembly within mesoporous TiO2 for solar cells[J]. Sol Energy, 2020, 196: 513-520. DOI: 10.1016/j.solener.2019.12.049.
[17] SUBILA K B, KUMAR G K, SHIVAPRASAD S M, et al. Luminescence properties of CdSe quantum dots: Role of crystal structure and surface composition[J]. J Phys Chem Lett, 2013, 4: 2774-2779. DOI: 10.1021/jz401198e.
[18] ZHAO M, CHEN Y, HAN R C, et al. A facile synthesis of biocompatible, glycol chitosan shelled CdSeS/ZnS QDs for live cell imaging[J]. Colloid. Surface, B, 2018, 9:4691. DOI: 10.1016/j.colsurfb.2018.09.002.
[19] 陈嘉顺.水溶性CdSe量子点的相关生物学效应研究[D].扬州:扬州大学,2016. DOI:10.7666/d.Y3611796.
[20] 岑雯雯.胶体CdSe量子点的光谱学研究[D].长春:东北师范大学,2021. DOI:10.27011/d.cnki.gdbsu.2021.001537.
[21] WANG B W, LIU L M, ZHANG Y, et al. A novel strategy for boosting the photoluminescence quantum efficiency of CdSe nanocrystals at room temperature[J]. Chin Chem Lett, 2020, 31(1):295-298. DOI: 10.1016/j.cclet.2019.03.043.
[22] XIE P, XUE S L, WANG Y Y, et al. Morphology-controlled synthesis of CdSe microspheres on graphene oxide sheets and their photocatalytic properties[J]. Ceram Int, 2016, 42(16): 18264-18270. DOI: 10.1016/j.ceramint.2016.08.151.
[23] BELLACANZONE C, TARPANI L, GENTILI P L, et al. Effects of glutathione on the luminescent behavior of CdSe-nanocrystals[J]. J Lumin, 2020, 226:117513. DOI: 10.1016/j.jlumin.2020.117513. (
