Impact of in-situ annealing on dilute-bismide materials and its application to photovoltaics

Autor: Adam W. Wood, Thomas F. Kuech, Susan E. Babcock, Kangho Kim, Kamran Forghani, Luke J. Mawst, Jae-Gyoung Lee, Yingxin Guan, Honghyuk Kim
Rok vydání: 2016
Předmět:
Zdroj: Journal of Crystal Growth. 452:276-280
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2016.04.039
Popis: GaAs 1− x Bi x /GaAs multiple quantum well heterostructures were grown by organo-metallic vapor phase epitaxy (OMVPE) at low temperatures and were subsequently in-situ annealed under an arsine (AsH 3 ) overpressure in the OMVPE reactor. Photoluminescence (PL) measurements were performed to establish the optimized annealing condition for the highest luminescence intensity, as well as high resolution X-ray diffraction (XRD) measurements to detect any structural changes after annealing. In addition, the complex compositional profile and the interfacial abruptness were deduced from the combined XRD analysis with the transmission electron microscopy. A 5-fold increase in the PL intensity at room temperature was observed after annealing under the optimized conditions. Using the optimized annealing conditions, single junction solar cells (SJSC) incorporating 5-period GaAs 0.964 Bi 0.036 /GaAs (32 nm/20 nm) heterostructures for the device base region were fabricated and characterized. The spectral dependence of the external quantum efficiency of the SJSC exhibited improved spectral response as a result of the optimized in-situ annealing, with extended absorption edge up to 1.07 eV.
Databáze: OpenAIRE
Externí odkaz: