The determination of extinction coefficient of CuInS2, and ZnCuInS3 multinary nanocrystals

Abstract

A pioneering work for determining the extinction coefficient of colloidal semiconductor nanocrystals (NCs) has been cited over 1500 times (W. Yu, W. Guo, X. G. Peng, Chem. Mater., 2003, 15, 2854-2860), indicating the importance of calculating NC concentration for further research and applications. In this study, the size-dependent nature of the molar extinction coefficient of "greener" CuInS(2) and ZnCuInS(3) NCs with emission covering the whole visible to near infrared (NIR) is presented. With the increase of NC size, the resulting quantitative values of the extinction coefficients of ternary CuInS(2) and quaternary ZnCuInS(3) NCs are found to follow a power function with exponents of 2.1 and 2.5, respectively. Obviously, a larger value of extinction coefficient is observed in quaternary NCs for the same size of particles. The difference of the extinction coefficient from both samples is clearly demonstrated due to incorporating ZnS with a much larger extinction coefficient into CuInS(2) NCs.

Size-Dependent Band-Gap and Molar Absorption Coefficients of Colloidal CuInS2 Quantum Dots

“…We also address the size-dependence of the band gap of chalcopyrite (cp) CIS QDs by reanalyzing experimental data published by several groups. 51,52,54−57 Our results demonstrate that the molar absorption coefficients of wz CIS QDs follow a power law with an exponent of 2.45 at first exciton transition energy and scale with the QD volume at 3.1 eV.…”

“…40,41,51,52,55−58,61 However, it is as yet unclear whether the wide tunability of the optical properties of CIS NCs (and other ternary copper chalcogenides) can be attributed solely to quantum confinement effects, in striking contrast with the II–VI, IV–VI, and III–V binary analogues. 40 The foremost difference between ternary copper (and silver) chalcogenides (I–III–VI 2 ) and binary II–VI and IV–VI compounds is that the former can easily tolerate large deviations from stoichiometry, both in the I/III ratio and VI/(I + III) ratio, resulting in a rich defect chemistry.…”

“…49,50 However, despite the importance of these nanomaterials, there are at present only two reports on the size-dependence of the molar absorption coefficients of CIS QDs. 51,52 Intriguingly, the size dependence of the ε values at the first exciton transition energy ( E 1 ) reported in these works is dramatically different: Qin et al . 51 reported a power law with an exponent of 2.1, while Booth et al .…”

“…51,52 Intriguingly, the size dependence of the ε values at the first exciton transition energy ( E 1 ) reported in these works is dramatically different: Qin et al . 51 reported a power law with an exponent of 2.1, while Booth et al . 52 found a power law with an exponent of 3.7.…”

Large-scale synthesis of single-source, thermally stable, and dual-emissive Mn-doped Zn–Cu–In–S nanocrystals for bright white light-emitting diodes

“…As the next generation color converters, scattering--free/scattering-less colloidal semiconductor nanocrystals (NCs) have higher luminescence efficiency, larger molar absorptivity and color tunability in comparison with traditional phosphors [9][10][11][12], which have been proven as promising color converters for WLEDs [13][14][15]. Various NCs such as ZnCdS [16][17][18][19][20][21], CdSe [22][23][24][25][26], ZnCdSe [27], CuInS [28][29][30][31][32][33][34][35], and InP [36][37][38][39][40][41] NCs have been successfully applied in the fabrication of WLEDs to enhance the color properties of the device.…”