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Pure ZnO and copper (IB group), sodium (IA group) and potassium (IA group) and doped ZnO thin films on glass substrate by chemical bath deposition method have been studied for Hall effect measurements, resistivity, Raman and photoluminescence (PL). The influence of dopant content on carrier concentration, electrical resistivity, and Hall mobility of the thin films are analyzed. Electrical conductivity measurements of ZnO are carried out by two probe method and activation energy for the electrical conductivity of pure and doped ZnO is found out. The Raman scattering of the pure ZnO and doped ZnO shows the first and second orders of polar and non-polar modes. Raman spectra confirms the hexagonal wurtzite structure of pure and doped ZnO with E 2 (high) mode at 439 cm −1 and presence of other possible defects. Photoluminescence (PL) at room temperature results indicate the emission occurs at close band lines and the outcomes are identified with a few inherent imperfections in the doped ZnO thin films. The PL results demonstrate the upgraded optoelectronic properties, specifically, the carriers for long life span is executed by the oxygen opportunities. Raman spectroscopy and photoluminescence confirm existence of zinc interstitials (Zni) as well as oxygen vacancies (Vo). Resistivity as low as 15 Ω-cm, Hall mobility as high as 6.2 cm 2 /Vs and effective carrier concentration as high as 1.70×10 17 e − /cm 3 have been obtained.

It is found in this study that four amino acids, namely asparagine, arginine, histidine and glutamine form two-dimensional conducting systems which are charge transfer complexes (CTCs) with organic acceptors like TCNQ, TCNE, chloranil, DDQ, TNF and iodine. It is verified using optical absorption edges that these are 2d conductors like transition metal dichalcogenides obeying absorption functions different from 1d and 3d conductors. This 2d nature is related to the network of intermolecular H-bonding in these complexes, which leads to a global H-bonded network resulting in the absence of local deformation due to the relaxation of strain.

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Zinc sulfide (ZnS) thin films were deposited onto microscopic silica slides through the cost-effective chemical bath deposition (CBD) method. The optimized bath parameters were: 25 ml of 0.1 M zinc precursors (ZnCl 2 , Zn(CH 3 COO) 2 , ZnSO 4 ), 25 ml of 1 M thiourea and 3 ml of 3.75 M triethanolamine (TEA). The effects of different zinc precursors (ZnCl 2 , Zn(CH 3 COO) 2 , ZnSO 4 ) on the growth mechanism of ZnS thin film were investigated using thermal, structural, morphological, optical and electrical studies. The XRD pattern has shown Miller indexing peaks corresponding to the hexagonal phase of as-grown ZnS thin film with the estimated grain size of 22 -27 nm. The change in physical properties (weight loss) of ZnS powder as a function of temperature was recorded using thermogravimetry (TGA/DTA). Scanning electron microscopy (SEM) revealed the effect of ZnCl 2 , Zn(CH 3 COO) 2 and ZnSO 4 precursors on growth mechanism. UV/visible optical transmission/absorption spectra displayed the transmittance between 10 to 29 % of as-grown ZnS thin film with a band gap in the range of 4.10 -4.25 eV. Photoluminescence (PL) analyses demonstrated broad blue emission around ∼ 459 nm was attributed to recombination of electron-hole pair from donor-acceptor trap levels to valance band. Raman spectra of ZnS powder prepared using different zinc precursors were also reported. The values of electrical parameters (resistivity, conductivity, activation energy, Hall coefficient, carrier concentration, mobility) were investigated using the two-point probe method and Hall-effect apparatus.