CdS超微粒的表面修饰行为及其光学特性
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摘要
硫化镉是典型的Ⅱ-Ⅵ族过渡金属化合物荧光半导体材料。硫化镉超微粒子具有独特的光电性质,可作为生物荧光标记材料,其激发谱线单一、发光效率高、发光颜色可调、可进行多色联合标记,在生物、医学等研究领域有着广阔的应用前景。
本文以硝酸镉和硫代乙酰胺为原料,巯基乙酸为表面修饰剂,水相制备功能性硫化镉超微粒。考察了巯基乙酸与硝酸镉的摩尔比、硫代乙酰胺与硝酸镉的摩尔比、反应初始溶液pH、反应温度、反应时间以及反应物的浓度、分散剂等条件对制备硫化镉粒子结构、粒度和性质的影响,采用X射线衍射、扫描电子显微镜、红外光谱、紫外.可见吸收光谱、荧光光谱分析对样品的结构、形貌、粒度及其分布、表面基团、光谱性质等进行了表征。结果表明:巯基乙酸的介入既可以减慢Cd~(2+)同S~(2-)反应的速度,并抑制CdS粒子之间团聚行为,从而减小晶粒粒度,又能自组装在CdS粒子的表面上,改善表面结构,提高荧光性能,并使其具有良好的水溶性,同时起到分散剂与修饰剂的作用,即强化材料性能的同时实现材料间性能的集成,达到了复合与组装的目的;反应物浓度、反应物配比和反应时间是影响CdS超微粒粒度及其分布的最主要因素,进而对CdS超微粒的物理化学性质有着重要的影响;实验最佳条件为:硝酸镉和硫代乙酰胺的浓度为0.1mol/L,巯基乙酸的浓度为0.2mol/L,体系pH=9,反应温度100℃,反应时间60min,此时得到的CdS超细粒子粒径小,粒度分布窄,带隙发射荧光强度高,吸收边陡峭,表面包覆的水溶性基团特征峰显著;CdS/-SCH_2COOH溶胶放置6个月无沉淀产生,稳定性好。
该法制备功能性硫化镉超微粒具有操作简单、制备与表面修饰一体化、粉末晶型稳定、粒度可控、水溶性好、稳定性高等优点。
Cadmium sulfide is the tipical transition metal compound of the II-VI Group Elements.As fluorescent semiconductor materials, CdS ultrafine particle has unique photoelectric properties, which can be used as bioluminescence markers materials.
In this paper, a new synthesis method of preparing functional CdS ultrafine particles in aqueous phase was proposed respectively using cadmium nitrate and thioacetamide as the source of Cd and S and using thioglycolic acide as surface-modifying agent. The effects of molar ratio of cadmium nitrate and thioglycolic acide, molar ratio of cadmium nitrate and thioacetamide, initial pH value of solution, temperature, reaction time, reactant concentration and additives on structure and morphologies and photoelectric properties of products were experimentally investigated. The structure, morphology, particle size and its distribution, surface groups and spectral properties of the products were characterized by XRD, SEM, FT-IR, Uv-Vis and PL analysis, individually.
The results indicate that adding thioglycolic acide can slower reaction rate of Cd~(2+) and S~(2-), inhibit agglomeration of CdS particles, decrease their grain sizes, improve their surface structures and fluorescence properties, and make them exhibit good solubility in water. The CdS particles prepared in optimum conditions have smaller particle sizes and more narrow size distribution, higher fluorescence intensity from bandgap emission, abrupt absorption edge, obvious surface group characteristic peaks, and their solution has been stable for six months.
The preparation method for CdS has such advantages as simple operation, integration between preparation and surface modification, and the functional CdS ultrafine particles exhibit stable structure,, controllable particle size, good water-soluble and stability.
本文以硝酸镉和硫代乙酰胺为原料,巯基乙酸为表面修饰剂,水相制备功能性硫化镉超微粒。考察了巯基乙酸与硝酸镉的摩尔比、硫代乙酰胺与硝酸镉的摩尔比、反应初始溶液pH、反应温度、反应时间以及反应物的浓度、分散剂等条件对制备硫化镉粒子结构、粒度和性质的影响,采用X射线衍射、扫描电子显微镜、红外光谱、紫外.可见吸收光谱、荧光光谱分析对样品的结构、形貌、粒度及其分布、表面基团、光谱性质等进行了表征。结果表明:巯基乙酸的介入既可以减慢Cd~(2+)同S~(2-)反应的速度,并抑制CdS粒子之间团聚行为,从而减小晶粒粒度,又能自组装在CdS粒子的表面上,改善表面结构,提高荧光性能,并使其具有良好的水溶性,同时起到分散剂与修饰剂的作用,即强化材料性能的同时实现材料间性能的集成,达到了复合与组装的目的;反应物浓度、反应物配比和反应时间是影响CdS超微粒粒度及其分布的最主要因素,进而对CdS超微粒的物理化学性质有着重要的影响;实验最佳条件为:硝酸镉和硫代乙酰胺的浓度为0.1mol/L,巯基乙酸的浓度为0.2mol/L,体系pH=9,反应温度100℃,反应时间60min,此时得到的CdS超细粒子粒径小,粒度分布窄,带隙发射荧光强度高,吸收边陡峭,表面包覆的水溶性基团特征峰显著;CdS/-SCH_2COOH溶胶放置6个月无沉淀产生,稳定性好。
该法制备功能性硫化镉超微粒具有操作简单、制备与表面修饰一体化、粉末晶型稳定、粒度可控、水溶性好、稳定性高等优点。
Cadmium sulfide is the tipical transition metal compound of the II-VI Group Elements.As fluorescent semiconductor materials, CdS ultrafine particle has unique photoelectric properties, which can be used as bioluminescence markers materials.
In this paper, a new synthesis method of preparing functional CdS ultrafine particles in aqueous phase was proposed respectively using cadmium nitrate and thioacetamide as the source of Cd and S and using thioglycolic acide as surface-modifying agent. The effects of molar ratio of cadmium nitrate and thioglycolic acide, molar ratio of cadmium nitrate and thioacetamide, initial pH value of solution, temperature, reaction time, reactant concentration and additives on structure and morphologies and photoelectric properties of products were experimentally investigated. The structure, morphology, particle size and its distribution, surface groups and spectral properties of the products were characterized by XRD, SEM, FT-IR, Uv-Vis and PL analysis, individually.
The results indicate that adding thioglycolic acide can slower reaction rate of Cd~(2+) and S~(2-), inhibit agglomeration of CdS particles, decrease their grain sizes, improve their surface structures and fluorescence properties, and make them exhibit good solubility in water. The CdS particles prepared in optimum conditions have smaller particle sizes and more narrow size distribution, higher fluorescence intensity from bandgap emission, abrupt absorption edge, obvious surface group characteristic peaks, and their solution has been stable for six months.
The preparation method for CdS has such advantages as simple operation, integration between preparation and surface modification, and the functional CdS ultrafine particles exhibit stable structure,, controllable particle size, good water-soluble and stability.
引文
[1] 杨媛媛,王新强,何阿玲.Ⅱ-Ⅵ族化合物中原子间两体及三体相互作用势的理论研究.功能材料,2007,38(8):1234-1237
[2] 平贵臣,曹立新,王丽颖,等.CdS半导体纳米颗粒的复合与组装.化学通报,2000,(2):32-36
[3] 李启厚.湿化学法制备ZnS、CdS纳米粉末结构形貌控制及其组装行为研究.长沙:中南大学,2001:3-4
[4] 张俊松,马娟,周益明,等.低温固相反应法合成水分散性CdS纳米晶.合成无机化学学报,2005,21(2):295-297
[5] Acioli L HA, Gomes A S L, Leite J R S. Measurement of high-order optical nonlinear susceptibilities in semiconductor-doped glasses. Appl Phys Lett, 1988, 53 (19): 1788-1792
[6] 张勇,王民权.非线性光学材料的研究进展.材料学报,1996,4:8-14
[7] Alivisatos A.P.,Seniconductor Clus-ters,Nanocrystals,and Quantum Dots, Science, 1996,271 (5480): 933-937
[8] 徐力,郭轶,解仁国,等.水相合成CdS纳米晶标记牛血清白蛋白.功能材料与器件学报,2003,9(2):201-204
[9] 王乐余,周运友,朱昌青,等.功能性CdS纳米荧光探针荧光增敏法测定人血清白蛋白.高等学校化学学报,2003,24(4):612-614
[10] 王乐余,郭畅,李茂国,等.功能性硫化镉纳米荧光探针荧光猝灭法测定核酸.分析化学,2003,31(1):83-86
[11] 陈旭东,王新波,范丽,等.CdS纳米晶与多肽相互作用研究.化学学报,2005,63(17):1600-1606
[12] 李志强,田少华,宋伟朋,等.(Zn,Cd)S:Cu,Cl发光材料的热释发光.发光学报,2005,26(3):316-318
[13] 崔一平,韩旭东,王著元,等.量子点发光材料及其在照明光源器件中的应用.照明工程学报,2005,16(1):11-14
[14] 冯新星,陈建勇,张建春.用丝素膜制备的纳米CdS及其光催化活性研究.功能高分子学报,2003,16(4):513-516
[15] 陈友存,叶信宇.纳米CdS微粒的制备、表征及光催化性质研究.安庆师范学院学报,2003,9(2):1-3
[16] Vered Pardo-Yissar, EugeniiKatz, JulianWasserman, et al. Acetylcholine esterase- labeled CdS nanoparticles onelectrodes: photoelectrochemical sensing of the enzyme in-hibitors. J Am Chem Soc, 2003,125: 622-623
[17] 王文忠,谭琳.低温固相合成形貌和晶相可控的CdS纳米晶.中央民族大学学报(自然科学版),2008,17(1):5-9
[18] 张俊松,马娟,周益明,等.低温固相反应法合成水分散性CdS纳米晶.无机化学学报,2005,21(2):295-297
[19] 苏凌浩,张校刚.脲酶诱发均匀沉淀法室温制备纳米CdS.功能材料与器件学报,2005,11(3):273-276
[20] 张言波,邵华锋,钱雪峰,等.单分散球形硫化镉粒子的制备及其形貌控制.无机材料学报,2005,20(3):575-579
[21] 黄风华,彭亦如.表面修饰的CdS纳米荧光探针的研究.光谱学与光谱分析,2006,26(6):1102-1105
[22] 曹维良,张凯华,张敬畅.表面修饰纳米CdS制备中两个重要影响因素及结构表征.无机化学学报,2002,18(10):997-1002
[23] 李恒达,王庆伟,翟宏菊,等.“反胶团法”合成的CdS半导体纳米粒子的光谱性质研究.光谱学与光谱分析,2008,28(7):1573-1577
[24] 王莹,乔燕,杨平,等.反胶束法合成CdS纳米粒子及其表征.化学研究与应用,2007,19(9):994-998
[25] 方鹏飞,高远鹏.等级状CdS树枝晶的形貌控制及生长机理.武汉大学学报(理学版),2008,54(3):313-316
[26] 汤嘉立,吴访升,陈铭.溶剂热合成单分散硫化镉纳米晶.化学学报,2008,66(14):1647-1650
[27] 刘春霞,严文,范新会,等.用热蒸发法制备CdS纳米带.材料科学与工程学报,2005,23(1):102-104.
[28] 于灵敏,范新会,刘春霞,等.外加电场对硫化镉晶须生长的影响研究.材料科学与工程学报,2004,22(3):414-416.
[29] 牛新书,刘艳丽,徐甲强,等.纳米硫化锌的合成研究.无机盐工业,2002,34(3):3-4
[30] 陈志刚,陈建峰,刘润静,等.无机纳米粉体制造技术的现状及展望.无机盐工业,2002,34(3):18-21
[31] 张皓,杨柏.荧光纳米晶制备及其与聚合物的复合组装.高等学校化学学报,2008,29(2):217-219
[32] 张立德,牟季美.纳米材料和纳米结构.北京:科学出版社,2001
[33] 王益林,陆建平,童张法,等.功能性CdS纳米颗粒的制备与性质.江西师范大学学报,2008,32(1):112-115
[34] 经斌,黄怡,陈佑宁,等.单源前体合成水溶性的CdS和ZnS纳米晶.无机化学学报,2007,23(5):928-932
[35] 汪乐余,高峰,张明翠,等.功能性纳米溶胶CdS的合成与荧光性质研究.安徽师范大学学报(自然科学版),2001,24(3):236-237
[36] 容敏智,章明秋,梁海春,等.原位表面修饰纳米CdS粒子的表面结构和光学性能.材料研究学报,2004,18(4):343-351
[37] 刘辉,李文友,尹洪宗,等.CdS纳米粒子与半胱氨酸相互作用的研究.高等学校化学学报,2005,26(9):1618-1622
[38] Chen Y F, Rosenzweig Z. Luminescent CdS quantumdots as selective ion probes.AnalChem, 2002, 74(19): 5132-5138
[39] Kerim M, Gattas A, RogerM, et al. Peptide-coatedCdS quantum dots for the optical detection of copperand silver. Chemcomm, 2003, 38(21): 2684-2685
[40] DubertretB, Skourides P,AlbertL,et al. In vivo ima-ging of quantum dots encapsulated in phospholipidmicelles. Science, 2002,298 (5599): 1759-1762
[41] HanM Y, GaoX H, Nie SM, et al. Quantum-dot-taggedmicrobeads formultiplexed optical coding ofbiomolecules. Nature biotechnology, 2001, 19(7): 631-635
[42] Chan P M, Yuen T, Sealfon S C, et al. Method formultiplex cellular detection ofmRNAs using quantumdot fluorescent in situ hybridization. NucleicAcidsResearch, 2005, 33(18): e161
[43] Warren C W, Nie S M. Quantum dots bioconjugates for ultrasensitive nonisotopic detection. Science, 1998,281(5385): 2016-2018.
[44] Sun B Q, XieW Z, Yi G S, et al. Microminiaturizeimmunoassays using quantum dots as fluorescent label by laser confocal scanning fluorescence detection. Journal of ImmunologicalMethods, 2001,24(1): 85-89
[45] Goldman E R, AndersonG P, MattoussiH, etal. Prep-aration of quantum dot-biotin conjugates and theiruse in immunochromatography assays. AnalChem, 2003,7516: 4043-4049.
[46] Goldman E R, Anderson G P, MattoussiH, et al. Multiplexed toxin analysis using four colors of quan-tum dot fluororeagents. Anal Chem, 2004, 76(3): 684-688
[47] Bakalova R, Zhelev Z,OhbaH, et al. Quantum dot-based western blot technology for ultrasensitive detec-tion of tracer proteins. JAm Chem Soc, 2005, 127(26): 9328-9329
[48] R.Premachandran, S Banerjee, V T John, et al. The Enzymatic Synthesis of Thiol-containing Polymers to Prepare Polymer-CdS Nanocomposites. Chem.Mater., 1997,9:1342
[49] 容敏智,章明秋,梁海春,等.原位表面修饰纳米CdS粒子的表面结构和光学性能.材料研究学报,2004,18(4):343-351
[50] 郭应臣,卓立宏,乔占平.表面修饰CdS和(CdS)ZnS纳米晶的性能研究.化学研究与应用,2007,19(1):37-41
[51] Y.Nosaka, N.Ohta, T.Fukuyama et al. Size Control of Ultrasmall CdS Particles in Aqueous Solution by Using Various Thiols. Journal of Colloid and Interface Science, 1993,155:23
[52] 娄文静,陈淼.有机-无机复合CdS纳米晶的制备及表征.材料科学与工程学报,2005,23(6):891-894
[53] 容敏智,章明秋,梁海春,等.修饰纳米CdS/聚合物的界面相互作用与光学性能.材料研究学报,2004,18(2):130-138
[54] W. William Yu, Lianhua Qu, Wenzhuo Guo et al.Experimental Determination of the Extinction Coefficient of CdTe, CdSe,and CdS Nanocrystals. Chem. Mater., 2003,15(14),2854-2860
[55] 刘国根,王丽群,龙怀中.现代仪器分析.北京:当代中国出版社,2003
[56] Tito T D, Paul O B, Nigel L P. Nanocrystalline semiconductors: synthesis, properties and perspectives. Chem Mater, 2001,13(1):3843-3858.
[2] 平贵臣,曹立新,王丽颖,等.CdS半导体纳米颗粒的复合与组装.化学通报,2000,(2):32-36
[3] 李启厚.湿化学法制备ZnS、CdS纳米粉末结构形貌控制及其组装行为研究.长沙:中南大学,2001:3-4
[4] 张俊松,马娟,周益明,等.低温固相反应法合成水分散性CdS纳米晶.合成无机化学学报,2005,21(2):295-297
[5] Acioli L HA, Gomes A S L, Leite J R S. Measurement of high-order optical nonlinear susceptibilities in semiconductor-doped glasses. Appl Phys Lett, 1988, 53 (19): 1788-1792
[6] 张勇,王民权.非线性光学材料的研究进展.材料学报,1996,4:8-14
[7] Alivisatos A.P.,Seniconductor Clus-ters,Nanocrystals,and Quantum Dots, Science, 1996,271 (5480): 933-937
[8] 徐力,郭轶,解仁国,等.水相合成CdS纳米晶标记牛血清白蛋白.功能材料与器件学报,2003,9(2):201-204
[9] 王乐余,周运友,朱昌青,等.功能性CdS纳米荧光探针荧光增敏法测定人血清白蛋白.高等学校化学学报,2003,24(4):612-614
[10] 王乐余,郭畅,李茂国,等.功能性硫化镉纳米荧光探针荧光猝灭法测定核酸.分析化学,2003,31(1):83-86
[11] 陈旭东,王新波,范丽,等.CdS纳米晶与多肽相互作用研究.化学学报,2005,63(17):1600-1606
[12] 李志强,田少华,宋伟朋,等.(Zn,Cd)S:Cu,Cl发光材料的热释发光.发光学报,2005,26(3):316-318
[13] 崔一平,韩旭东,王著元,等.量子点发光材料及其在照明光源器件中的应用.照明工程学报,2005,16(1):11-14
[14] 冯新星,陈建勇,张建春.用丝素膜制备的纳米CdS及其光催化活性研究.功能高分子学报,2003,16(4):513-516
[15] 陈友存,叶信宇.纳米CdS微粒的制备、表征及光催化性质研究.安庆师范学院学报,2003,9(2):1-3
[16] Vered Pardo-Yissar, EugeniiKatz, JulianWasserman, et al. Acetylcholine esterase- labeled CdS nanoparticles onelectrodes: photoelectrochemical sensing of the enzyme in-hibitors. J Am Chem Soc, 2003,125: 622-623
[17] 王文忠,谭琳.低温固相合成形貌和晶相可控的CdS纳米晶.中央民族大学学报(自然科学版),2008,17(1):5-9
[18] 张俊松,马娟,周益明,等.低温固相反应法合成水分散性CdS纳米晶.无机化学学报,2005,21(2):295-297
[19] 苏凌浩,张校刚.脲酶诱发均匀沉淀法室温制备纳米CdS.功能材料与器件学报,2005,11(3):273-276
[20] 张言波,邵华锋,钱雪峰,等.单分散球形硫化镉粒子的制备及其形貌控制.无机材料学报,2005,20(3):575-579
[21] 黄风华,彭亦如.表面修饰的CdS纳米荧光探针的研究.光谱学与光谱分析,2006,26(6):1102-1105
[22] 曹维良,张凯华,张敬畅.表面修饰纳米CdS制备中两个重要影响因素及结构表征.无机化学学报,2002,18(10):997-1002
[23] 李恒达,王庆伟,翟宏菊,等.“反胶团法”合成的CdS半导体纳米粒子的光谱性质研究.光谱学与光谱分析,2008,28(7):1573-1577
[24] 王莹,乔燕,杨平,等.反胶束法合成CdS纳米粒子及其表征.化学研究与应用,2007,19(9):994-998
[25] 方鹏飞,高远鹏.等级状CdS树枝晶的形貌控制及生长机理.武汉大学学报(理学版),2008,54(3):313-316
[26] 汤嘉立,吴访升,陈铭.溶剂热合成单分散硫化镉纳米晶.化学学报,2008,66(14):1647-1650
[27] 刘春霞,严文,范新会,等.用热蒸发法制备CdS纳米带.材料科学与工程学报,2005,23(1):102-104.
[28] 于灵敏,范新会,刘春霞,等.外加电场对硫化镉晶须生长的影响研究.材料科学与工程学报,2004,22(3):414-416.
[29] 牛新书,刘艳丽,徐甲强,等.纳米硫化锌的合成研究.无机盐工业,2002,34(3):3-4
[30] 陈志刚,陈建峰,刘润静,等.无机纳米粉体制造技术的现状及展望.无机盐工业,2002,34(3):18-21
[31] 张皓,杨柏.荧光纳米晶制备及其与聚合物的复合组装.高等学校化学学报,2008,29(2):217-219
[32] 张立德,牟季美.纳米材料和纳米结构.北京:科学出版社,2001
[33] 王益林,陆建平,童张法,等.功能性CdS纳米颗粒的制备与性质.江西师范大学学报,2008,32(1):112-115
[34] 经斌,黄怡,陈佑宁,等.单源前体合成水溶性的CdS和ZnS纳米晶.无机化学学报,2007,23(5):928-932
[35] 汪乐余,高峰,张明翠,等.功能性纳米溶胶CdS的合成与荧光性质研究.安徽师范大学学报(自然科学版),2001,24(3):236-237
[36] 容敏智,章明秋,梁海春,等.原位表面修饰纳米CdS粒子的表面结构和光学性能.材料研究学报,2004,18(4):343-351
[37] 刘辉,李文友,尹洪宗,等.CdS纳米粒子与半胱氨酸相互作用的研究.高等学校化学学报,2005,26(9):1618-1622
[38] Chen Y F, Rosenzweig Z. Luminescent CdS quantumdots as selective ion probes.AnalChem, 2002, 74(19): 5132-5138
[39] Kerim M, Gattas A, RogerM, et al. Peptide-coatedCdS quantum dots for the optical detection of copperand silver. Chemcomm, 2003, 38(21): 2684-2685
[40] DubertretB, Skourides P,AlbertL,et al. In vivo ima-ging of quantum dots encapsulated in phospholipidmicelles. Science, 2002,298 (5599): 1759-1762
[41] HanM Y, GaoX H, Nie SM, et al. Quantum-dot-taggedmicrobeads formultiplexed optical coding ofbiomolecules. Nature biotechnology, 2001, 19(7): 631-635
[42] Chan P M, Yuen T, Sealfon S C, et al. Method formultiplex cellular detection ofmRNAs using quantumdot fluorescent in situ hybridization. NucleicAcidsResearch, 2005, 33(18): e161
[43] Warren C W, Nie S M. Quantum dots bioconjugates for ultrasensitive nonisotopic detection. Science, 1998,281(5385): 2016-2018.
[44] Sun B Q, XieW Z, Yi G S, et al. Microminiaturizeimmunoassays using quantum dots as fluorescent label by laser confocal scanning fluorescence detection. Journal of ImmunologicalMethods, 2001,24(1): 85-89
[45] Goldman E R, AndersonG P, MattoussiH, etal. Prep-aration of quantum dot-biotin conjugates and theiruse in immunochromatography assays. AnalChem, 2003,7516: 4043-4049.
[46] Goldman E R, Anderson G P, MattoussiH, et al. Multiplexed toxin analysis using four colors of quan-tum dot fluororeagents. Anal Chem, 2004, 76(3): 684-688
[47] Bakalova R, Zhelev Z,OhbaH, et al. Quantum dot-based western blot technology for ultrasensitive detec-tion of tracer proteins. JAm Chem Soc, 2005, 127(26): 9328-9329
[48] R.Premachandran, S Banerjee, V T John, et al. The Enzymatic Synthesis of Thiol-containing Polymers to Prepare Polymer-CdS Nanocomposites. Chem.Mater., 1997,9:1342
[49] 容敏智,章明秋,梁海春,等.原位表面修饰纳米CdS粒子的表面结构和光学性能.材料研究学报,2004,18(4):343-351
[50] 郭应臣,卓立宏,乔占平.表面修饰CdS和(CdS)ZnS纳米晶的性能研究.化学研究与应用,2007,19(1):37-41
[51] Y.Nosaka, N.Ohta, T.Fukuyama et al. Size Control of Ultrasmall CdS Particles in Aqueous Solution by Using Various Thiols. Journal of Colloid and Interface Science, 1993,155:23
[52] 娄文静,陈淼.有机-无机复合CdS纳米晶的制备及表征.材料科学与工程学报,2005,23(6):891-894
[53] 容敏智,章明秋,梁海春,等.修饰纳米CdS/聚合物的界面相互作用与光学性能.材料研究学报,2004,18(2):130-138
[54] W. William Yu, Lianhua Qu, Wenzhuo Guo et al.Experimental Determination of the Extinction Coefficient of CdTe, CdSe,and CdS Nanocrystals. Chem. Mater., 2003,15(14),2854-2860
[55] 刘国根,王丽群,龙怀中.现代仪器分析.北京:当代中国出版社,2003
[56] Tito T D, Paul O B, Nigel L P. Nanocrystalline semiconductors: synthesis, properties and perspectives. Chem Mater, 2001,13(1):3843-3858.