Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Growth of Highly Doped P-type ZnTe Films by Pulsed Laser Ablation in Molecular Nitrogen
Author: Highly Doped P-ZnTe Films and Quantum Well Structures Grown by Nonequilibrium Pulsed Laser Ablation
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Highly p-doped ZnTe films have been grown on semi-insulating GaAs (001) and unintentionally doped (p-type) GaSb (001) substrates by pulsed KrF (248 nm) excimer laser ablation of a ZnTe target through an N[sub 2] ambient, without the use of any assisting (DC or AC) plasma source. Free hole concentrations in the mid-10[sup 19] cm[sup[minus]3] to> 10[sup 20] cm[sup[minus]3] range have been obtained. This appears to be the first time that any wide band gap (E[sub g][ge] 2 eV) II-VI compound (or other) semiconductor has been impurity-doped from the gas phase by pulsed-laser ablation (PLA). The maximum carrier concentrations also may be the highest obtained for ZnTe by any method thus far. Because pulsed laser deposition is inherently digital, attractive deposition rates can be combined with precise control of layer thickness in epitaxial multilayered structures. Typical deposition conditions are
Concepte der Reichskammergerichtsordnung
Author: Film Synthesis and Growth Using Energetic Beams: Volume 388
Author: H. A. AtwaterPublisher:
ISBN:
Category : Science
Languages : en
Pages : 472
Book Description
With over 16 countries represented, this book represents international developments in the field of film synthesis and growth using energetic beams. It focuses on pulsed-laser deposition. Fundamental issues pertaining to the generation of laser ablation plumes, temperature distributions and collisional effects are described. Ion-assisted pulsed-laser deposition, pulsed-ion deposition, applications of hyperthermal beams and aspects of surface dynamics are discussed. The inclusion of an ion beam with the ablation process leads to some unique modifications in the thin-film growth mechanisms, and hence, film properties. Likewise, the collision of high-mass metal cluster ions with substrates shows promise for growth of novel structures. Also featured are new developments of optoelectronic materials, nitrides and carbon films using a variety of techniques. The effects of beam-induced defects on growth and surface morphology, chemical effects during growth, and characterization of film growth and film properties are addressed.
Scientific and Technical Aerospace Reports
Author: LEOS ...
Author: Laser Ablation and Desorption
Author: Publisher: Academic Press
ISBN: 0080860206
Category : Technology & Engineering
Languages : en
Pages : 671
Book Description
This volume introduces the subject of laser ablation and desorption to scientists and engineers. It covers fundamental experimental and theoretical tools, models, and techniques, and introduces the most important applications. Clearly written and organized in a straightforward manner, Laser Ablation and Desorption lead the reader straight through the fundamentals of laser-surface interactions. Each chapter is self-contained and includes references to other chapters as necessary, so that readers may begin with the topic of greatest interest and follow the references to other aspects of the subject contained within the book. Key Features * Provides up-to-date information about one of the most active fields in physics today * Written and edited by major figures in the field of laser ablation and desorption * Represents the most comprehensive treatment of the state-of-the-art available
Energy Research Abstracts
Author: Government Reports Announcements & Index
Author: Omvpe Growth and Characterization of Znse Based Materials for Blue-green Laser Applications
Author: Milind R GokhalePublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :
Book Description
Blue-green light emitting diodes and lasers have been the driving force behind the dramatic improvement in the growth technology of ZnSe based II-VI materials. While blue-green laser diodes grown by molecular beam epitaxy are a reality, OMVPE (organometallic vapor phase epitaxy) grown p-n junction lasers have remained elusive. This study involves the growth of undoped films using a photoassisted low-temperature technique. Also, doping studies were undertaken to achieve n- and p-type ZnSe using chlorine and nitrogen, respectively. A simulation of the ZnSe/ZnTe MQW contacts to p-ZnSe is also reported. High temperature ZnSe films grown using dialkyl sources DMZn and DMSe, have been found to exhibit undesirable yellow emissions from self-activated deep levels. A study of an alternate low-temperature, UV light assisted technique for the growth of high optical quality ZnSe films is presented. We have shown an interplay of UV intensity and temperature in determining the optical quality of these layers. A temperature dependent UV intensity threshold, above which specular morphology and suppression of the deep level emissions has been observed. By the use of cadmium doping a further reduction in deep-level yellow emissions is achieved. Properties of n-type photoassisted ZnSe films co-doped with Cd and Cl have also been investigated. The samples co-doped with Cd showed increased incorporation of the Cl donors. By the use of Cd co-doping, we have achieved the highest electron concentration yet reported $(2\times10\sp#x18;\ \rm cm\sp{-3})$ for HCl doping of OMVPE-grown ZnSe. We propose a model based on the compensation of tetrahedral misfit to explain these results. The nitrogen doping of ZnSe to achieve p-type conductivity was studied using tertiarybutyl amine as dopant source. The level of nitrogen incorporation was determined from the structure of the donor-acceptor pair (DAP) emissions in the photoluminescence spectrum. The effects of growth temperature, UV intensity during growth, and dopant flow on the incorporation of nitrogen in ZnSe layers have been investigated. Nitrogen concentrations comparable to MBE-grown ZnSe:N films, were obtained for lower growth temperatures and reduced UV intensities. Most of the ZnSe:N films were highly resistive indicating hydrogen passivation of nitrogen acceptors.