Title :
Perpendicular transport of photoexcited carriers influenced by heterointerface disorder in GaAs/AlAs superlattices
Author :
Yamada, M. ; Yamamoto, Y. ; Ikemoto, T. ; Nogami, T. ; Fujiwara, K.
Author_Institution :
Kyushu Inst. of Technol., Kitakyushu, Japan
Abstract :
Perpendicular tunneling transport of photoexcited carriers sinking into an intentionally enlarged GaAs single quantum well (SQW) in GaAs/AlAs short-period superlattices (SPS) is investigated as a function of lattice temperature (T) by steady-state and time-resolved photoluminescence (TR-PL) experiments. By measuring PL signals from SPS as well as from SQW to monitor the transport efficiency, it is found that, while a weak ambipolar tunneling-assisted hopping conduction prevails at lower T via localized states formed due to heterointerface disorder within the SPS layer, the Bloch-type transport is observed due to thermal activation of photoexcited carriers to the extended miniband states at T>30 K. This temperature evolution of the perpendicular transport is directly evidence by TR-PL measurements and rigorously explained by a rate equation analysis
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; hopping conduction; interface states; photoconductivity; photoluminescence; semiconductor quantum wells; semiconductor superlattices; time resolved spectra; tunnelling; 30 K; Bloch-type transport; GaAs-AlAs; GaAs/AlAs short-period superlattices; GaAs/AlAs superlattices; PL signals; enlarged GaAs single quantum well; extended miniband states; heterointerface disorder; lattice temperature; localized states; perpendicular transport; photoexcited carriers; rate equation analysis; steady-state photoluminescence; temperature evolution; thermal activation; time-resolved photoluminescence; tunneling transport; weak ambipolar tunneling-assisted hopping conduction; Equations; Gallium arsenide; Lattices; Monitoring; Photoluminescence; Steady-state; Superlattices; Temperature; Thermal conductivity; Tunneling;
Conference_Titel :
Semiconducting and Insulating Materials Conference, 2000. SIMC-XI. International
Conference_Location :
Canberra, ACT
Print_ISBN :
0-7803-5814-7
DOI :
10.1109/SIM.2000.939237
