Time-resolved PL and TEM studies of MOVPE-grown bulk dilute nitride and bismide quantum well heterostructure

Yongkun Sin, Zachary Lingley, Mark Peterson, Miles Brodie, Steven C. Moss, Tae Wan Kim, Honghyuk Kim, Yingxin Guan, K. Forghani, Luke J. Mawst, Thomas F. Kuech

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Among several approaches proposed to achieve high-efficiency III-V multi-junction solar cells, the most promising approach is to incorporate a bottom junction consisting of a 1 - 1.25 eV material. In particular, several research groups have studied MBE- and MOVPE-grown 1 - 1.25 eV bulk (In)GaAsN(Sb) dilute nitride lattice matched to GaAs substrates, but it is a challenge to grow dilute nitrides without introducing a number of localized states or defects. Localized states originating from random distributions of nitrogen sites in dilute nitrides behave as highly efficient traps, leading to short minority carrier lifetimes. As our group previously reported, carrier dynamics studies are indispensable in the optimization of dilute nitride materials growth to achieve improved solar cell performance. Also, bismide QW heterostructures have recently received a great deal of attention for applications in solar cells and semiconductor lasers because theoretical studies have predicted reduction in nonradiative recombination in Bicontaining materials. For the present study, we employed time-resolved photoluminescence (TR-PL) techniques to study carrier dynamics in MOVPE-grown bulk (In)GaAsN(Sb) materials nominally lattice matched to GaAs substrates. Compared to our previous samples, our present samples grown using different metalorganic precursors at higher growth temperatures showed a significantly less background C doping density. Carrier lifetimes were measured from such dilute nitride samples with low C doping density at various temperatures between 10K and RT. We also performed preliminary TR-PL measurements on MOVPE-grown bismide QW heterostructures at low temperatures. Carrier lifetimes were measured from as-grown and annealed bismide QW structures consisting of GaAsBi(P) wells and GaAsP barriers. Lastly, TEM cross sections were prepared from both dilute nitride and bismide samples for defect and composition analysis using a high resolution TEM.

Original languageEnglish
Title of host publicationPhysics, Simulation, and Photonic Engineering of Photovoltaic Devices IV
EditorsMasakazu Sugiyama, Alexandre Freundlich, Jean-Francois Guillemoles
ISBN (Electronic)9781628414486
StatePublished - 2015
EventPhysics, Simulation, and Photonic Engineering of Photovoltaic Devices IV - San Francisco, United States
Duration: 10 Feb 201512 Feb 2015

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferencePhysics, Simulation, and Photonic Engineering of Photovoltaic Devices IV
Country/TerritoryUnited States
CitySan Francisco


  • Dilute nitride
  • TEM
  • TR-PL
  • carrier dynamics
  • dilute bismide
  • multi-junction solar cell


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