Novel Materials and Technologies for IR Optoelectronic Applications
Doktorsavhandling, 2012

This thesis focuses on novel III-V materials (InAs/GaSb type-II superlattices, T2SL, and dilute bismides) and metamorphic growth techniques for infrared optoelectronics all of which may find wide spread applications in telecommunication, energy harvesting and saving, sensing and imaging. Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) photodetectors at the atmospheric windows of 3-5 and 8-12 µm, respectively, are currently dominated by HgCdTe and quantum well infrared photodetectors. These detectors, however, suffer from the suitability for making focal plane array (FPA) detectors due to the material non-uniformity or the low operation temperature that significantly increases the cost for a practical detection or imaging system. InAs/GaSb type-II superlattices are promising candidates for FPA detectors with better performance at a lower cost. Dilute bismides where a small amount of Bi atoms are incorporated into traditional host III-V semiconductors have theoretically shown a number of interesting physical properties. The large energy band bowing effect with retained transport and optical properties make these materials attractive for making short-wavelength infrared (SWIR), MWIR and LWIR optoelectronic devices. Dilute bismides have been only little studied among the III-V semiconductors, and in particular epitaxial growth of dilute III-SbBi is almost unexplored. Metamorphic growth is an efficient technique for lattice engineering and useful for device applications such as multi-junction solar cells, III-V and Si integration, electronic and optoelectronic devices on cheap substrates. Here, growth optimization and innovations to minimize threading dislocations are challenging and crucial for improving the material quality. The work in this thesis deals with issues related to the realization of these novel III-V materials and metamorphic growth techniques using molecular beam epitaxy (MBE). It is investigated how doping in alloy graded metamorphic buffers influences material quality and a new method to reduce dislocation density and improve optical quality by using dilute nitride buffer layers is demonstrated. Design and growth optimization of T2SL structures for mid-IR detectors are presented. MBE growth of novel dilute III-SbBi alloys is investigated. The growth of GaSbBi is reported for the first time. The abnormal lattice contraction of GaSbBi is discovered and explained.


dilute bismide

InAs/GaSb type-II superlattice



alloy graded buffer

threading dislocation


molecular beam epitaxy

Kollektorn (A423) at the Department of Microtechnology and Nanoscience (MC2), Kemivägen 9, Göteborg
Opponent: Professor Eric Tournie, Electric Engineering and Electronics Department, Université Montpellier 2-CNRS, France.


Yuxin Song

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Effects of doping and grading slope on surface and structure of metamorphic InGaAs buffers on GaAs substrates

Journal of Applied Physics,; Vol. 106(2009)p. 123531-

Artikel i vetenskaplig tidskrift

Investigation of metamorphic InGaAs quantum wells using N-incorporated buffer on GaAs grown by MBE

Journal of Crystal Growth,; Vol. 323(2011)p. 21-25

Artikel i vetenskaplig tidskrift

A study of the doping influence on strain relaxation of graded composition InGaAs layers grown by molecular beam epitaxy

Journal of Crystal Growth,; Vol. 311(2009)p. 1684-

Artikel i vetenskaplig tidskrift

Enhancement of optical quality in metamorphic quantum wells using dilute nitride buffers

Applied Physics Letters,; Vol. 97(2010)p. 091903-

Artikel i vetenskaplig tidskrift

Growth of GaSb1-xBix by molecular beam epitaxy

Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures,; Vol. 30(2012)p. Art. no. 02B114-

Artikel i vetenskaplig tidskrift



Annan materialteknik

Annan elektroteknik och elektronik

Den kondenserade materiens fysik



Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology: 212

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3318

Kollektorn (A423) at the Department of Microtechnology and Nanoscience (MC2), Kemivägen 9, Göteborg

Opponent: Professor Eric Tournie, Electric Engineering and Electronics Department, Université Montpellier 2-CNRS, France.