The energy barrier heights between two recently reported Ta-based amorphous metals (TaWSi and TaNiSi), TaN, and atomic layer deposited Al2O3 and HfO2 insulators are measured in metal/insulator/metal (MIM) structures with Au top electrodes using internal photoemission (IPE) spectroscopy. For Al2O3, the Ta-based metal barrier heights, phi(Bn), increase with increasing metal...
Transparent p – i – n heterojunction diodes are fabricated using heavily doped, p-type CuYO₂ and
semi-insulating i-ZnO thin films deposited onto a glass substrate coated with n-type indium tin
oxide. Rectification is observed, with a ratio of forward-to-reverse current as high as 60 in the range
−4–4 V. The...
The microscopic cause of conductivity in transparent conducting oxides like ZnO, In₂O₃, and SnO₂ is generally considered to be a point defect mechanism in the bulk, involving intrinsic lattice defects, extrinsic dopants, or unintentional impurities like hydrogen. We confirm here that the defect theory for O-vacancies can quantitatively account for...
InP/SiO₂ interfaces have been studied by high resolution electron microscopy in cross section, by ellipsometry, and by x-ray photoelectron spectroscopy. The roughness of the interface is shown to vary from 10 to 100 Å peak to peak depending on the InP surface treatment prior to SiO₂ desposition, and some evidence...
Vacuum ultraviolet reflectivity measurements of three thin-film electroluminescent phosphors, zinc sulfide (ZnS), strontium sulfide (SrS), and strontium-calcium thiogallate (Sr₀.₄₅Ca₀.₅₅Ga₂S₄), are reported using thin-film samples. Measured ZnS reflectivity peak positions are in agreement with values previously reported in the literature. SrS room temperature reflectivity measurements are found to be consistent with...
Highly transparent ZnO-based thin-film transistors (TFTs) are fabricated with optical transmission (including substrate) of ~75% in the visible portion of the electromagnetic spectrum. Current–voltage measurements indicate n-channel, enhancement-mode TFT operation with excellent drain current saturation and a drain current on-to-off ratio of ~10⁷. Threshold voltages and channel mobilities of devices...
The capacitance-voltage (C-V) technique is proposed as a method for characterization of the electrical properties of alternating-current thin-film electroluminescent (ACTFEL) display devices. Analysis of the C-V and aging characteristics of ZnS:Mn ACTFEL devices indicates that the C-V technique is complementary to the charge-voltage technique in the extraction of device physics...
Electroluminesence (EL) thermal quenching refers a reduction in luminance, concomitant with a reduction in transferred charge, when an alternating-current thin-film electroluminescent (ACTFEL) device is operated at an elevated temperature. EL thermal quenching is found to be significant in SrS:Cu ACTFEL devices operated above ~60-80 °C. Maximum transferred charge-maximum applied voltage...
White electroluminescence (EL) was observed for the first time from diamond-like carbon (DLC) films at room temperature. ac voltages in excess of 200 V were applied to a metal-insulator-semiconductor (i.e., DLC)-insulator-metal device structure to observe EL. At an applied voltage of 235 V, the brightness and efficiency were 0.5 fl...
Hot electron luminescence experiments are performed on ZnS alternating-current thin-film electroluminescent (ACTFEL) devices in order to determine the extent to which the electron distribution is heated. The luminescence spectrum is found to be broad and essentially featureless up to a high energy cutoff of approximately 3.7 eV, which is determined...