Hydrogenated amorphous silicon
PARC1
30 Aug 1991-pp 431
TL;DR: In this article, the electronic density of states of amorphous silicon and their electronic states have been investigated in terms of defect reactions, thermal equilibrium and metastability, as well as their electronic properties.
Abstract: 1. Introduction 2. Growth and structure of amorphous silicon 3. The electronic density of states 4. Defects and their electronic states 5. Substitutional doping 6. Defect reactions, thermal equilibrium and metastability 7. Electronic transport 8. Recombination of excess carriers 9. Contacts, interfaces and multilayers 10. Amorphous silicon device technology.
Citations
More filters
TL;DR: The role of extended and point defects, and key impurities such as C, O, and H, on the electrical and optical properties of GaN is reviewed in this article, along with the influence of process-induced or grown-in defects and impurities on the device physics.
Abstract: The role of extended and point defects, and key impurities such as C, O, and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation, and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes, and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.
1,693 citations
TL;DR: In this article, the authors show that the recombination kinetics of polymer BHJ cells evolve from first-order recombination at short circuit to bimolecular recombinations at open circuit as a result of increasing the voltage-dependent charge carrier density in the cell.
Abstract: Recombination of photogenerated charge carriers in polymer bulk heterojunction (BHJ) solar cells reduces the short circuit current $({J}_{sc})$ and the fill factor (FF). Identifying the mechanism of recombination is, therefore, fundamentally important for increasing the power conversion efficiency. Light intensity and temperature-dependent current-voltage measurements on polymer BHJ cells made from a variety of different semiconducting polymers and fullerenes show that the recombination kinetics are voltage dependent and evolve from first-order recombination at short circuit to bimolecular recombination at open circuit as a result of increasing the voltage-dependent charge carrier density in the cell. The ``missing 0.3 V'' inferred from comparison of the band gaps of the bulk heterojunction materials and the measured open-circuit voltage at room-temperature results from the temperature dependence of the quasi-Fermi levels in the polymer and fullerene domains---a conclusion based on the fundamental statistics of fermions.
1,637 citations
TL;DR: The fabrication of a-Si:H nanowires and nanocones function as both absorber and antireflection layers, which offer a promising approach to enhance the solar cell energy conversion efficiency.
Abstract: Hydrogenated amorphous Si (a-Si:H) is an important solar cell material. Here we demonstrate the fabrication of a-Si:H nanowires (NWs) and nanocones (NCs), using an easily scalable and IC-compatible process. We also investigate the optical properties of these nanostructures. These a-Si:H nanostructures display greatly enhanced absorption over a large range of wavelengths and angles of incidence, due to suppressed reflection. The enhancement effect is particularly strong for a-Si:H NC arrays, which provide nearly perfect impedance matching between a-Si:H and air through a gradual reduction of the effective refractive index. More than 90% of light is absorbed at angles of incidence up to 60° for a-Si:H NC arrays, which is significantly better than NW arrays (70%) and thin films (45%). In addition, the absorption of NC arrays is 88% at the band gap edge of a-Si:H, which is much higher than NW arrays (70%) and thin films (53%). Our experimental data agree very well with simulation. The a-Si:H nanocones functio...
1,238 citations
TL;DR: In this article, the effect of aluminum-doped zinc oxide (ZnO:Al) front contact and the role of the back reflector on the performance of thin-film silicon solar cells is investigated.
1,013 citations
TL;DR: The BOLS correlation mechanism has been initiated and intensively verified as discussed by the authors, which has enabled the tunability of a variety of properties of a nanosolid to be universally reconciled to the effect of bond order deficiency of atoms at sites surrounding defects or near the surface edges of the nano-material.
775 citations