Abstract
CuInS2 (CIS) quantum dots (QDs) with different diameters were prepared and their optical properties were studied. The optical band gap of QDs, as estimated by absorption spectrum, was found to decrease with increase in size. The stokes shift between absorption and photoluminescence peaks was observed to be larger (>100 meV) in all the three samples. This shows that the defect states available in the forbidden gap dominates the recombination mechanism. The variation in the emission peak with QD size, however, indicates that the relaxation dynamics in CIS QDs involves both excitonic level as well as the defect states.
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H. Mattoussi, L.H. Radzilowski, B.O. Dabbousi, E.L. Thomas, M.G. Bawendi, and M.F. Rubner: Electroluminescence from heterostructures of poly(phenylene vinylene) and inorganic CdSe nanocrystals. J. Appl. Phys. 83, 7965 (1998).
Y. Liu, Y. Li, L. Wang, B. Gu, W. Sang, Y. Gu, and X. Liu: The kinetics of the coordination transformation for preparation of nanosized CdS in a PVA film. J. Macromol. Sci. B 47, 230 (2008).
M.C. Schlamp, X. Peng, and A.P. Alivisatos: Improved efficiencies in light emitting diodes made with CdSe(CdS) core/shell type nanocrystals and a semiconducting polymer. J. Appl. Phys. 82, 5837 (1997).
X. Fang, Y. Bando, U.K. Gautam, T. Zhai, S. Gradecak, and D. Golberg: Heterostructures and superlattice in one-dimensional nanoscale semiconductors. J. Mater. Chem. 19, 5683 (2009).
P.K. Khanna and N. Singh: Light emitting CdS quantum dots in PMMA: synthesis and optical studies. J. Lumin. 127, 474 (2007).
K.J. Nordell, E.M. Boatman, and G.C. Lisensky: A safer, easier, faster synthesis for CdSe quantum dot nanocrystals. J. Chem. Educ. 82, 1697 (2005).
R. Genger, M. Grabolle, S. Cavaliere Jaricot, R. Nitschke, and T. Nann: Quantum dots versus organic dyes as fluorescence labels. Nat. Methods 5, 763 (2008).
O. Chen, J. Zhao, V.P. Chauhan, J. Cui, C. Wong, D.K. Harris, H. Wei, H.S. Han, D. Fukumura, R.K. Jain, and M.G. Bawendi: Compact high quality CdSe–CdS core shell nanocrystals with narrow emission linewidths and suppressed blinking. Nat. Mater. 12, 445 (2013).
S. Madan, J. Kumar, I. Singh, D. Madhwal, P.K. Bhatnagar, and P.C. Mathur: The effect of cadmium vacancies on the optical properties of chemically prepared CdS quantum dots. Phys. Scr. 82, 045702 (2010).
T. Omata, K. Nose, and S. Otsuka-Yao-Matsuo: Size dependent optical band gap of ternary I-III-VI2 semiconductor nanocrystals. J. Appl. Phys. 105, 073106 (2009).
E. Arici, N.S. Sariciftci, and D. Meissner: Hybrid solar cells based on nanoparticles of CuInS2 in organic matrices. Adv. Funct. Mater. 13, 165 (2003).
D.C. Pan, X.L. Wang, Z.H. Zhou, W. Chen, C.L. Xu, and Y.F. Lu: Synthesis of quaternary semiconductor nanocrystals with tunable band gaps. Chem. Mater. 21, 2489 (2009).
P.M. Allen and M.G. Bawendi: Ternary I–III–VI quantum dots luminescent in the red to nearinfrared. J. Am. Chem. Soc. 130, 9240 (2008).
W.S. Song and H. Yang: Efficient white light emitting diodes fabricated from highly fluorescent copper indium sulfide core/shell quantum dots. Chem. Mater. 24, 1961 (2012).
H.J. Lewerenz: Development of copper indium disulfide into a solar material. Sol. Energy Mater. Sol. Cells 83, 395 (2004).
K.M.A. Hussain, J. Podder, D.K. Saha, and M. Ichimura: Structural, electrical and optical characterization of CuInS2 thin films deposited by spray pyrolysis. Ind. J. Pure Appl. Phys. 50, 117 (2012).
C. Czekelius, M. Hilgendorff, L. Spanhel, I. Bodja, M. Lerch, G. Miller, U. Bloeck, D.S. Su, and M. Giersig: A simple collidal route to nanocrystalline ZnO/CuInS2 bilayers. Adv. Mater. 11, 643 (1999).
K. Mochizuki, E. Niwa, and K. Masumoto: Effects of heat treatment on the photoluminescence spectra in AgGaS2. J. Lumin. 51, 231 (1992).
S.C. Pandey and D. Maroudas: Equilibrium compositional distribution in freestanding ternary semiconductor quantum dots: the case of InxGa1−xAs. J. Chem. Phys. 135, 234701 (2011).
D. Nam, W. Seuk, and H. Yang: Facile, air-sensitive solvothermal synthesis of emission-tunable CuInS2/ZnS quantum dots with high quantum yields. J. Mater. Chem. 21, 18220 (2011).
T.L. Li and H. Teng: Solution synthesis of high quality CuInS2 quantum dots as sensitizers for TiO2 photoelectrodes. J. Mater. Chem. 20, 3656 (2010).
J.J. Nairn, P.J. Shapiro, B. Twamley, T. Pounds, R. vonWandruszka, T.R. Fletcher, M. Williams, C. Wang, and M.G. Norton: Preparation of ultrafast chalcopyrite nanoparticles via the photochemical decomposition of molecular single-source precursors. Nano Lett. 6, 1218 (2006).
Y. Hamanaka, T. Ogawa, M. Tsuzuki, and T. Kuzuya: Photoluminescence properties and its origin of AgInS2 quantum dots with chalcopyrite structure. J. Phys. Chem. C 115, 1786 (2011).
L. Li, A. Pandey, D.J. Werder, B.P. Khanal, J.M. Pietryga, and V.I. Klimov: Efficient synthesis of highly luminescent copper indium sulfide based core/shell nanocrystals with surprisingly long lived emission. J. Am. Chem. Soc. 133, 1176 (2011).
S.P. Mondal, H. Mulick, T. Layanya, A. Dhar, S.K. Ray, and S.K. Lahiri: Optical and dielectric properties of junctionlike CdS nanocomposites embedded in polymer matrix. J. Appl. Phys. 102, 064305 (2007).
J. Barman, K.C. Sarma, M. Sarma, and K. Sarma: Structural and optical studies of chemically prepared CdS nanocrytalline thinfilms. Ind. J. Pure Appl. Phys. 46, 339 (2008).
C.B. Murray, D.J. Norris, and M.G. Bawendi: Synthesis and characterization of nearly monodisperse CdE (E = S, Se, Te) semiconductor nanocrystallites. J. Am. Chem. Soc. 115, 8706 (1993).
D.G. Thomas, J.J. Hopfield, and W.M. Augustyniak: Kinetics of radiative recombination at randomly distributed donors and acceptors. Phys. Rev. 140, A202 (1965).
N. Satoh, K. Abe, K. Wakita, and K. Mochizuki: Growth of CuInS2 crystal from melt and their properties. Phys. Status Solidi 3, 2630 (2006).
Acknowledgments
The financial support from the Department of Science and Technology, India is gratefully acknowledged. The authors also acknowledge the University Science Instrumentation Centre, University of Delhi, India for TEM and EDAX measurements.
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Singh, I., Madan, S., Kaur, A. et al. Study of relaxation dynamics of photogenerated excitons in CuInS2 quantum dots. MRS Communications 4, 1–5 (2014). https://doi.org/10.1557/mrc.2014.5
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DOI: https://doi.org/10.1557/mrc.2014.5