Abstract: In various embodiments, light-emitting devices incorporate smooth contact layers and polarization doping (i.e., underlying layers substantially free of dopant impurities) and exhibit high photon extraction efficiencies.

Abstract: Reducing the microvoid (MV) density in AlN ameliorates numerous problems related to cracking during crystal growth, etch pit generation during the polishing, reduction of the optical transparency in an AlN wafer, and, possibly, growth pit formation during epitaxial growth of AlN and/or AlGaN. This facilitates practical crystal production strategies and the formation of large, bulk AlN crystals with low defect densities—e.g., a dislocation density below 104 cm?2 and an inclusion density below 104 cm?3 and/or a MV density below 104 cm?3.

Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.

Abstract: In various embodiments, single-crystal aluminum nitride boules and substrates are formed from the vapor phase with controlled levels of impurities such as carbon. Single-crystal aluminum nitride may be heat treated via quasi-isothermal annealing and controlled cooling to improve its ultraviolet absorption coefficient and/or Urbach energy.

Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density ?100 cm?2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Abstract: Provided is a novel chalcogen-containing organic semiconductor compound having excellent carrier mobility. The compound is represented by Formula (1a) or (1b): [Chem. 1] where in Formulas (1a) and (1b), X represents S, O, or Se, and R1 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a pyridyl group, a furyl group, a thienyl group, or a thiazolyl group.

Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density?100 cm?2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Abstract: In various embodiments, a rigid lens is attached to a light-emitting semiconductor die via a layer of encapsulant having a thickness insufficient to prevent propagation of thermal expansion mismatch-induced strain between the rigid lens and the semiconductor die.

Abstract: In various embodiments, single-crystal aluminum nitride boules and substrates having high transparency to ultraviolet light and low defect density are formed. The single-crystal aluminum nitride may function as a platform for the fabrication of light-emitting devices such as light-emitting diodes and lasers.

Abstract: In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.

Abstract: In various embodiments, methods of forming single-crystal AlN include providing a substantially undoped polycrystalline AlN ceramic having an oxygen concentration less than approximately 100 ppm, forming a single-crystal bulk AlN crystal by a sublimation-recondensation process at a temperature greater than approximately 2000° C., and cooling the bulk AlN crystal to a first temperature between approximately 1500° C. and approximately 1800° C. at a first rate less than approximately 250° C./hour.

Abstract: In various embodiments, an electrochemical process is utilized to remove at least a portion of a substrate from multiple singulated or unsingulated electronic-device or optoelectronic-device dies. The dies may be attached to a submount for the removal process, and the dies may be immersed in or non-immersively contact an electrolyte during the removal process.

Abstract: In various embodiments, extraction efficiency of light-emitting devices fabricated on aluminum nitride substrates is enhanced via removal of at least a portion of the substrate.

Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.

Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density?100 cm=2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.

Abstract: In various embodiments, growth of large, high-quality single crystals of aluminum nitride is enabled via a two-stage process utilizing two different crystalline seeds.

Abstract: In various embodiments, a rigid lens is attached to a light-emitting semiconductor die via a layer of encapsulant having a thickness insufficient to prevent propagation of thermal expansion mismatch-induced strain between the rigid lens and the semiconductor die.

Abstract: In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.

Abstract: Active matrix array devices are constituted by devices that have a function such as those of a display/light emitting device, a sensor, a memory or an actuator, and are arranged in a matrix array shape, and the expansion of usage in various fields and applications is expected. However, there is little similarity and compatibility in the forming process and materials between a device such as a display/light emitting device, a sensor, a memory, or an actuator, and a circuit portion that controls such a device in the matrix element, and therefore the device and the circuit portion are mutually restricting factors. This results in an increase in the manufacturing cost and limitation of the function. A conventional active matrix array device is manufactured by performing various process steps on the same substrate. Control circuit portions each including a transistor are formed in some of the process steps.