Application of Ge quantum wells fabricated by laser annealing as energy selective contacts for hot-carrier solar cells

Sammy Lee*, Shujuan Huang, Gavin Conibeer, Martin A. Green

*Corresponding author for this work

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

Abstract

In this study, a lower-cost and highly compatible laser scanning method was implemented as an alternative annealing process to fabricate quantum well (QW) structures. Ge QW films were fabricated by continuous-wave laser annealing and their potential for energy selective contact (ESC) applications was assessed by structural, optical and electrical characterization. The structural properties were observed by transmission electron microscopy (TEM), Raman spectroscopy and x-ray diffraction (XRD) techniques. Cross-sectional TEM images showed the dimension of the QWs to be larger along the direction of laser scanning. Uni-axial tensile strained film properties were found in XRD investigations which showed crystal growth favored in a series of orthogonal direction <110> along the laser scan direction due to the laser dragging the liquid phase Ge. Rapid quenching from liquefied Ge introduced stress in the film as shown by peak shifts in XRD and in Raman spectra. Despite that strong optical absorption by amorphous features in the film possibly hinder the quantum confinement presentation as shown in the absorption curves, Preliminary data, presenting tentative current fluctuations in the room temperature I-V measurement, suggest that a double barrier resonant tunneling structure is possible, showing its potential application for ESCs.

Original languageEnglish
Title of host publication2012 38th IEEE Photovoltaic Specialists Conference
Place of PublicationPiscataway, NJ
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Pages801-805
Number of pages5
ISBN (Electronic)9781467300667, 9781467300650
ISBN (Print)9781467300643
DOIs
Publication statusPublished - 2011
Externally publishedYes
Event38th IEEE Photovoltaic Specialists Conference, PVSC 2012 - Austin, TX, United States
Duration: 3 Jun 20128 Jun 2012

Publication series

Name
ISSN (Print)0160-8371

Conference

Conference38th IEEE Photovoltaic Specialists Conference, PVSC 2012
CountryUnited States
CityAustin, TX
Period3/06/128/06/12

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