II-VI/III-V Heterojunctions.
Abstract
Use of the Mg containing quaternary led to a pseudomorphic SCH laser. The graded bandgap ohmic contact reduced threshold voltages to 5 volts as room temperature cw was obtained. TEM studies provided the first reports of compositional modulation in a II-VI alloy. It was found that the quaternary above a certain bandgap exhibited a compositional modulation in a particular <110> direction. Laser degradation has been studied using electroluminescence microscopy and TEM of degraded devices. The microstructural analysis revealed that the degradation originated from stacking faults nucleated at or near the II-VI/III-V interface. Using etching techniques it was determined that room temperature cw lasers had stacking fault densities of 3x10(exp 5) to 1x10(exp 6)/sq cm. Recently we have emphasized reducing these densities. We have reached the 10(exp3)/sq cm and are consistently in the low 10(exp 4)/sq cm. It appears that the high resistivity observed in p-type wide bandgap alloys is the manifestation of a DX-like behavior. Although previous studies reported DX centers in many n-type semiconductors there are no previous report for acceptors in any p-type semiconductor; we named this phenomenon an AX center.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1995
- Accession Number
- ADA299965
Entities
People
- Robert L. Gunnshor
Organizations
- Purdue University