Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Thin, high quality GaInP compositionally graded buffer layers grown at high growth rates for metamorphic III-V solar cell applications
Year:2014
Research Areas
  • Electric engineers, electronic and automatic (eil),
  • Solar cells,
  • Technology of devices for engineering
Information
Abstract
The metamorphic growth of lattice-mismatched materials has allowed optimizing the bandgap combination in multijunction solar cells for the solar spectrum under consideration. Buffer structures are used to accommodate the lattice-mismatch by introducing dislocations and relaxing the material in a controlled way. However, the metamorphic buffers typically involve significant growth time and material usage, which increases the cost of these solar cells. In this work, the thinning of buffer structures with continuously, linearly graded misfit is addressed with the goal of increasing the cost-effectiveness of metamorphic multijunction solar cells. The relaxation dynamics and quality of the buffer layers analyzed were assessed by in-situ stress measurements and ex-situ measurements of residual strain, threading dislocation density and surface roughness. Their ultimate quality has been tested using these buffers as templates for the growth of 1 eV Ga0.73In0.27As solar cells. The deleterious effect of thinning the grade layer of these buffer structures from 2 to 1 mu m was investigated. it is shown that prompting the relaxation of the buffer by using a stepwise misfit jump at the beginning of the grade layer improves the quality of the thinned buffer structure. The residual threading dislocation density of the optimized thin buffers, grown at a high growth rate of 7 mu m/h, is 3 x 10(6) cm(-2), and solar cells on these buffers exhibit near-icleal carrier collection efficiency and a V-oc of 0.62 V at 1-sun direct terrestrial spectrum.
International
Si
JCR
Si
Title
Journal of Crystal Growth
ISBN
0022-0248
Impact factor JCR
1,693
Impact info
Volume
393
Journal number
From page
64
To page
69
Month
SIN MES
Ranking
Participants
  • Autor: Ivan Garcia Vara (UPM)
  • Autor: R.M. France
  • Autor: J.F. Geisz
  • Autor: J. Simon
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Semiconductores III-V
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física
S2i 2020 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)