Abstract:
A method for growing a Group II-VI epitaxial layer on a substrate, said epitaxial layer having an electron mobility greater than 1.5.times.10.sup.5 cm.sup.2 /V-sec at 77.degree. K. and a carrier concentration less than 4.times.10.sup.15 (cm.sup.-3) is described. The method includes the steps of directing a plurality of vapor flows towards the substrate including a Group II metalorganic vapor having a mole fraction in the range of 3.0.times.10.sup.-4 to 4.5.times.10.sup.-4, a Group VI metalorganic vapor having a mole fraction in the range of 2.9.times.10.sup.-3 to 3.5.times.10.sup.-3 and a Group II elemental metal vapor having a mole fraction in the range of 2.6.times.10.sup.-2 to 3.2.times.10.sup.-2. The source of Group II metal is heated to at least 240.degree. C. while radiant energy is directed toward the reactor vessel to warm the zone of the reactor vessel between the Group II metal source and the substrate to at least 240.degree. C. The directed flows of Group II metalorganic vapor, Group VI metalorganic vapor and Group II metal vapor then chemically react to form the epitaxial layer.
Abstract:
Disclosed is a method of growing a layer of CdTe on HgCdTe by liquid phase epitaxy. The solution for growth comprises Sn and Hg with a small amount of CdTe. A typical composition is Sn:Hg:CdTe=36:5:0.15 parts by weight. The growth temperature is a function of the amount of CdTe in solution. For the typical composition stated, the growth temperature is about 520.degree. C. The layers were grown on (111)A oriented CdTe substrates. The HgCdTe epilayer with a desired Cd composition is first grown, and an epilayer of CdTe is subsequently grown on the HgCdTe epilayer. The cross-diffusion at the CdTe/Hg.sub.1-x Cd.sub.x Te interface has been as small as 0.3 .mu.m for the thin CdTe epilayer. The first CdTe/HgCdTe heterojunction sensitive to .about.2.8 .mu.m at 77K has been demonstrated.
Abstract:
Embodiments provided herein describe methods for forming cadmium-manganese-telluride (CMT), such as for use in photovoltaic devices. A substrate including a material with a zinc blend crystalline structure is provided. CMT is formed above the substrate. During the formation of the CMT, cation-rich processing conditions are maintained. The resulting CMT may be more readily provided with p-type dopants when compared to conventionally-formed CMT.
Abstract:
A method and apparatus for controlling and changing the composition of a cadmium zinc telluride (CZT) transition layer as it is formed over a partially completed photovoltaic device using electrochemical deposition (ECD) where plating variables are systematically changed while the CZT transition layer is formed to change the composition of the plated CZT transition layer.
Abstract:
Provided is a CdTe-based semiconductor substrate for epitaxial growth, which is capable of growing good-quality epitaxial crystals without urging a substrate user to implement etching treatment before the epitaxial growth.A CdTe-based semiconductor substrate, in which tracks of linear polishing damage with a depth of 1 nm or more are not observed within a viewing range of 10 μm×10 μm when a surface of the substrate is observed by an atomic force microscope, and orange peel defects are not observed when the surface of the substrate is visually observed under a fluorescent lamp, can grow the good-quality epitaxial crystals.
Abstract:
A semiconductor nanocrystal heterostructure has a core of a first semiconductor material surrounded by an overcoating of a second semiconductor material. Upon excitation, one carrier can be substantially confined to the core and the other carrier can be substantially confined to the overcoating.
Abstract:
Provided is a CdTe-based semiconductor substrate for epitaxial growth, which is capable of growing good-quality epitaxial crystals without urging a substrate user to implement etching treatment before the epitaxial growth.A CdTe-based semiconductor substrate, in which tracks of linear polishing damage with a depth of 1 nm or more are not observed within a viewing range of 10 μm×10 μm when a surface of the substrate is observed by an atomic force microscope, and orange peel defects are not observed when the surface of the substrate is visually observed under a fluorescent lamp, can grow the good-quality epitaxial crystals.
Abstract:
A semiconductor nanocrystal heterostructure has a core of a first semiconductor material surrounded by an overcoating of a second semiconductor material. Upon excitation, one carrier can be substantially confined to the core and the other carrier can be substantially confined to the overcoating.
Abstract:
A semiconductor nanocrystal heterostructure has a core of a first semiconductor material surrounded by an overcoating of a second semiconductor material. Upon excitation, one carrier can be substantially confined to the core and the other carrier can be substantially confined to the overcoating.