Shape Controlled Plasmonic Sn Doped CdO Colloidal Nanocrystals: A Synthetic Route to Maximize the Figure of Merit of Transparent Conducting Oxide

Abstract

The synthesis of different anisotropic shaped (eight different shapes) Sn doped CdO (Sn:CdO) colloidal nanocrystals (NCs) by precise tuning of precursor reactivity and proper choice of capping agent is reported. In all these systems, formation of Sn:CdO quantum dots (QDs) of 2-3 nm is identified at very early stage of reaction. The colloidally stable QDs act as a continuous source for the formation of primary nanoparticles that can be transformed selectively into specific type of nanoparticle morphology. The specific facet stabilization of fcc (face centered cubic)CdO is predicted by particular choice of ligand. Fine tuning of plasmonic absorbance band can be achieved by variation of Sn doping concentration. Different anisotropic Sn:CdO NCs exhibit interesting shape dependent plasmonic absorbance features in NIR region. High quality crack free uniform dense thin film has been deposited on glass substrate to make high quality transparent conducting oxide (TCO) coatings. figure of merit of TCO can be maximized as high as 0.523 Ω with conductivity of 43 600 S cm and visible transmittance of ≈85% which is much higher than commercially available tin doped indium oxide and other transparent electrodes.

Analysis of Sn Concentration Effect on Morphological, Optical, Electrical and Photonic Properties of Spray-Coated Sn-Doped CdO Thin Films

“…Similarly, a small change in growth temperature can also change the crystallite orientation. A same trend of XRD peak intensity reversion depending on substrate temperature and an increase in Sn-doping concentration has also been reported in the literature [20,[26][27][28]. Zhao et al [20] and Gupta et al [26] showed temperature-dependent crystallite orientation change in Sn-doped CdO thin films prepared by MOCVD and pulsed laser deposition (PLD), respectively.…”

“…Zheng et al [27] showed crystallite orientation change in PLD-prepared Sn-doped CdO thin films due to the variation in Sn-doping concentration. Ghosh et al [28] reported growth condition-dependent change in crystallite orientation of Sn-doped CdO synthesized by solution route. Figure 2 shows the XRD pattern of the films prepared using different volumes of cadmium acetate (0.05 M) and SnCl 4 (0.3 mM).…”

Plasmon-induced carrier polarization in semiconductor nanocrystals

“…9 Subsequently, different dopants were introduced into In2O3, including, Ti, Sb, Ce and Mo, to tune to plasmon frequency from NIR to MIR. 12,[30][31] Many other types of metal oxides substitutionally doped with high-valence-cations have been extensively studied in the search of plasmonic semiconductor nanomaterials, including ZnO doped with Al, Ga, and In; 16 CdO doped with Dy, In, and Sn; 17,[32][33] TiO2 doped with Nb; 19 SnO2 doped with Sb, 18 etc. In these degenerately doped semiconductor NCs, the dopants substitute the lattice cations and cause the shift of the Fermi level depending on the energetic alignment of the dopant orbitals with the conduction band of metal oxides.…”

Prediction of Novel p‐Type Transparent Conductors in Layered Double Perovskites: A First‐Principles Study

“…Transparent conductive oxides (TCOs) are widely studied TCs. Whereas n ‐type TCOs, including substitutionally doped In 2 O 3 , SnO 2 , ZnO, and CdO, have already been applied in many modern devices, their p ‐type counterparts are rarely seen and have not been largely commercialized due to the p ‐type doping difficulty in wide‐gap oxides. Generally, the p ‐type doping difficulty in TCOs lies in the fact that their valence band maximum (VBM) with O‐2 p characters has a very low absolute energy, which is very difficult for p ‐type dopants to create shallow defect levels for good p ‐type doping performance .…”