Optical properties and dynamics of direct and spatially and momentum indirect excitons in AlGaAs/AlAs quantum wells
Abstract: We present an experimental study on optical properties and dynamics of direct and spatially and momentum indirect excitons in AlGaAs/AlAs quantum wells near the crossover between $\varGamma-$ and $X$-valley confined electron states. The time-integrated photoluminescence experiment at $T=$4.8 K revealed three simultaneously observed optical transitions resulting from (a) a direct exciton recombination, involving an electron and a hole states both located in the $\varGamma$-valley in the quantum well layer, and (b) two spatially and momentum indirect excitons, comprising of the confined electron states in the $X$-valley in the AlAs barrier with different effective masses and quantum well holes in the $\varGamma$-valley. This interpretation has been based on the optical pumping density-dependent, temperature-dependent and spatially-resolved photoluminescence measurements, which provided the characterization of the structure, crucial in potential system's applications. Additionally, the time-resolved photoluminescence experiments unveiled complex carrier relaxation dynamics in the investigated quantum well system, which is strongly governed by a non-radiative carrier recombination - the characteristics further critical in potential system's use. This solid state platform hosting both direct and indirect excitons in a highly tunable monolithic system can benefit and underline the operation principles of novel electronic and photonic devices.
- Gu, J. et al. Dipolar excitonic insulator in a moiré lattice. \JournalTitleNature Physics 18, 395–400, DOI: 10.1038/s41567-022-01532-z (2022).
- High-temperature superfluidity with indirect excitons in van der waals heterostructures. \JournalTitleNature Communications 5, 4555, DOI: 10.1038/ncomms5555 (2014).
- Condensation of Indirect Excitons in Coupled AlAs/GaAs Quantum Wells. \JournalTitlePhysical Review Letters 73, 304–307, DOI: 10.1103/PhysRevLett.73.304 (1994).
- Towards bose–einstein condensation of excitons in potential traps. \JournalTitleNature 417, 47–52, DOI: 10.1038/417047a (2002).
- Wang, Z. et al. Evidence of high-temperature exciton condensation in two-dimensional atomic double layers. \JournalTitleNature 574, 76–80, DOI: 10.1038/s41586-019-1591-7 (2019).
- Excitonic devices with van der waals heterostructures: valleytronics meets twistronics. \JournalTitleNature Reviews Materials 7, 449–464, DOI: 10.1038/s41578-021-00408-7 (2022).
- Liu, Y. et al. Excitonic devices based on two-dimensional transition metal dichalcogenides van der waals heterostructures. \JournalTitleFrontiers of Chemical Science and Engineering 18, 16, DOI: 10.1007/s11705-023-2382-0 (2024).
- Optical study of alxga1-xas-alas ternary alloy multi-quantum-well structures around two γ−x𝛾𝑥\gamma{-}xitalic_γ - italic_x crossovers. \JournalTitleJournal of the Physical Society of Japan 57, 4403–4408, DOI: 10.1143/jpsj.57.4403 (1988).
- Photoluminescence decay time studies of type II GaAs/AlAs quantum-well structures. \JournalTitleJournal of Applied Physics 65, 3606–3609, DOI: 10.1063/1.342640 (1989).
- Determination of xzsubscript𝑥𝑧{\mathit{x}}_{\mathit{z}}italic_x start_POSTSUBSCRIPT italic_z end_POSTSUBSCRIPT-xx,subscript𝑥𝑥{\mathit{x}}_{\mathit{x},}italic_x start_POSTSUBSCRIPT italic_x , end_POSTSUBSCRIPTy energy separation and intervalley relaxation times in type-ii alxsubscriptal𝑥{\mathrm{al}}_{\mathit{x}}roman_al start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPTga1−xsubscriptga1𝑥{\mathrm{ga}}_{1\mathrm{-}\mathit{x}}roman_ga start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPTas/alas multiple quantum wells. \JournalTitlePhys. Rev. B 42, 11434–11437, DOI: 10.1103/PhysRevB.42.11434 (1990).
- Lee, S. T. et al. Interband transitions in alxsubscriptal𝑥{\mathrm{al}}_{\mathit{x}}roman_al start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPTga1−xsubscriptga1𝑥{\mathrm{ga}}_{1\mathrm{-}\mathit{x}}roman_ga start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPTas/alas quantum-well structures. \JournalTitlePhys. Rev. B 53, 12912–12916, DOI: 10.1103/PhysRevB.53.12912 (1996).
- Haetty, J. et al. Magnetic-field-induced localization of carriers in al0.25ga0.75As/AlAssubscriptal0.25subscriptga0.75AsAlAs{\mathrm{al}}_{0.25}{\mathrm{ga}}_{0.75}\mathrm{A}\mathrm{s}/\mathrm{A}\mathrm% {l}\mathrm{A}\mathrm{s}roman_al start_POSTSUBSCRIPT 0.25 end_POSTSUBSCRIPT roman_ga start_POSTSUBSCRIPT 0.75 end_POSTSUBSCRIPT roman_As / roman_AlAs multiple-quantum-well structures. \JournalTitlePhys. Rev. B 56, 12364–12368, DOI: 10.1103/PhysRevB.56.12364 (1997).
- ΓΓ\Gammaroman_Γ-X mixing in GaAs/Alx𝑥{}_{x}start_FLOATSUBSCRIPT italic_x end_FLOATSUBSCRIPTGa1−x1𝑥{}_{1-x}start_FLOATSUBSCRIPT 1 - italic_x end_FLOATSUBSCRIPTAs and Alx𝑥{}_{x}start_FLOATSUBSCRIPT italic_x end_FLOATSUBSCRIPTGa1−x1𝑥{}_{1-x}start_FLOATSUBSCRIPT 1 - italic_x end_FLOATSUBSCRIPT As/AlAs superlattices. \JournalTitlePhysical Review B 36, 4359–4374, DOI: 10.1103/PhysRevB.36.4359 (1987).
- Ru, G. et al. Gamma-X band mixing in GaAs/AlAs superlattice. vol. 5260, 257, DOI: 10.1117/12.544034 (2003).
- Spectroscopic determination of the bandgap crossover composition in mbe-grown alxga1-xas. \JournalTitleJapanese Journal of Applied Physics 54, 042402, DOI: 10.7567/JJAP.54.042402 (2015).
- Chand, N. et al. Comprehensive analysis of si-doped alxga1−xAssubscriptal𝑥subscriptga1𝑥As{\mathrm{al}}_{x}{\mathrm{ga}}_{1-x}\mathrm{As}roman_al start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPT roman_ga start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPT roman_As (x=0𝑥0x=0italic_x = 0 to 1111): Theory and experiments. \JournalTitlePhys. Rev. B 30, 4481–4492, DOI: 10.1103/PhysRevB.30.4481 (1984).
- Pearah, P. J. et al. Low-temperature optical absorption in AlxGa1-xAs grown by molecular-beam epitaxy. \JournalTitlePhys. Rev. B 32, 3857–3862, DOI: 10.1103/PhysRevB.32.3857 (1985).
- Tada, T. et al. Tunneling process in AlAs/GaAs double quantum wells studied by photoluminescence. \JournalTitleJournal of Applied Physics 63, 5491–5494, DOI: 10.1063/1.340374 (1988).
- Feldmann, J. et al. ΓΓ\Gammaroman_Γ-X-ΓΓ\Gammaroman_Γ electron transfer in mixed type I-type II GaAs/AlAs quantum well structures. \JournalTitleSolid State Communications 83, 245–248, DOI: 10.1016/0038-1098(92)90846-2 (1992).
- Order of the X conduction-band valleys in type-II GaAs/AlAs quantum wells. \JournalTitlePhysical Review B 39, 13426–13433, DOI: 10.1103/PhysRevB.39.13426 (1989).
- Birkedal, D. et al. Interwell excitons in GaAs superlattices. \JournalTitleSuperlattices and Microstructures 21, 587–590, DOI: 10.1006/spmi.1996.0208 (1997).
- Type-I – type-II transition in ultra-short-period GaAs/AlAs superlattices. \JournalTitlePhysical Review B 40, 6101–6107, DOI: 10.1103/PhysRevB.40.6101 (1989).
- ΓΓ\Gammaroman_Γ - X crossover in GaAs/AlAs superlattices. \JournalTitleSolid State Communications 70, 535–539, DOI: 10.1016/0038-1098(89)90945-9 (1989).
- Peterson, M. W. et al. Miniband dispersion in GaAs/Alx𝑥{}_{x}start_FLOATSUBSCRIPT italic_x end_FLOATSUBSCRIPTGa1−x1𝑥{}_{1-x}start_FLOATSUBSCRIPT 1 - italic_x end_FLOATSUBSCRIPTAs superlattices with wide wells and very thin barriers. \JournalTitleApplied Physics Letters 53, 2666–2668, DOI: 10.1063/1.100189 (1988).
- Danan, G. et al. Optical evidence of the direct-to-indirect-gap transition in GaAs-AlAs short-period superlattices. \JournalTitlePhysical Review B 35, 6207–6212, DOI: 10.1103/PhysRevB.35.6207 (1987).
- Suchomel, H. et al. Room temperature strong coupling in a semiconductor microcavity with embedded AlGaAs quantum wells designed for polariton lasing. \JournalTitleOptics Express 25, 24816, DOI: 10.1364/OE.25.024816 (2017).
- Exciton and trion spectral line shape in the presence of an electron gas in GaAs/AlAs quantum wells. \JournalTitlePhysical Review B - Condensed Matter and Materials Physics 54, DOI: 10.1103/PhysRevB.54.10609 (1996).
- Syperek, M. et al. Spin coherence of holes in GaAs/(Al,Ga)As quantum wells. \JournalTitlePhysical Review Letters 99, DOI: 10.1103/PhysRevLett.99.187401 (2007).
- Spatial variations of photoluminescence line broadening around oval defects in gaas/algaas multiple quantum wells. \JournalTitleSemiconductor Science and Technology 7, A59, DOI: 10.1088/0268-1242/7/1A/011 (1992).
- Ihm, J. Effects of the layer thickness on the electronic character in GaAs-AlAs superlattices. \JournalTitleApplied Physics Letters 50, 1068–1070, DOI: 10.1063/1.97972 (1987).
- Fabrication and optical properties of semiconductor quantum wells and superlattices. \JournalTitleProgress in Quantum Electronics 14, 289–356, DOI: 10.1016/0079-6727(90)90001-E (1990).
- Effective mass and ground state of AlAs quantum wells studied by magnetoresistance measurements. \JournalTitleJournal of Applied Physics 71, 296–299, DOI: 10.1063/1.350704 (1992).
- Rotation of the conduction band valleys in alas due to XXsubscript𝑋𝑋{X}_{X}italic_X start_POSTSUBSCRIPT italic_X end_POSTSUBSCRIPT- XYsubscript𝑋𝑌{X}_{Y}italic_X start_POSTSUBSCRIPT italic_Y end_POSTSUBSCRIPT mixing. \JournalTitlePhys. Rev. Lett. 83, 3693–3696, DOI: 10.1103/PhysRevLett.83.3693 (1999).
- Piprek, J. Semiconductor optoelectronic devices (Elsevier, 2003).
- Pietka, B. Excitonic Complexes in Natural Quantum Dots Formed in Type II GaAs / AlAs. Physics [physics]. Ph.D. thesis, Université Joseph-Fourier - Grenoble I, Grenoble (2007).
- Theory of two-dimensional spatially indirect equilibrium exciton condensates. \JournalTitlePhys. Rev. B 92, 165121, DOI: 10.1103/PhysRevB.92.165121 (2015).
- k-space formulation of ΓΓ\Gammaroman_Γ-x mixing for excitons in a thin gaas/alas quantum well. \JournalTitlePhys. Rev. B 49, 5438–5442, DOI: 10.1103/PhysRevB.49.5438 (1994).
- Self-consistent approach for calculations of exciton binding energy in quantum wells. \JournalTitlePhysica E: Low-dimensional Systems and Nanostructures 25, 539–553, DOI: https://doi.org/10.1016/j.physe.2004.08.111 (2005).
- Finkman, E. et al. Optical properties and band structure of short-period GaAs/AlAs superlattices. \JournalTitleJournal of Luminescence 39, 57–74, DOI: 10.1016/0022-2313(87)90033-0 (1987).
- Coulomb effects in spatially separated electron and hole layers in coupled quantum wells. \JournalTitleJournal of Experimental and Theoretical Physics 92, 260–266, DOI: 10.1134/1.1354683 (2001).
- Magneto-optics of the spatially separated electron and hole layers in gaas/alxga1−xAsgaassubscriptal𝑥subscriptga1𝑥As{\mathrm{g}\mathrm{a}\mathrm{a}\mathrm{s}/\mathrm{a}\mathrm{l}}_{x}{\mathrm{ga% }}_{1-x}\mathrm{As}roman_gaas / roman_al start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPT roman_ga start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPT roman_As coupled quantum wells. \JournalTitlePhys. Rev. B 60, 8753–8758, DOI: 10.1103/PhysRevB.60.8753 (1999).
- Excitation-power dependence of the near-band-edge photoluminescence of semiconductors. \JournalTitlePhys. Rev. B 45, 8989–8994, DOI: 10.1103/PhysRevB.45.8989 (1992).
- Excitation-intensity dependence of shallow and deep-level photoluminescence transitions in semiconductors. \JournalTitleJournal of Applied Physics 126, 175703, DOI: 10.1063/1.5095235 (2019).
- Screening of the electron-hole interaction in quantum well structures. \JournalTitleSuperlattices and Microstructures 1, 149–151, DOI: https://doi.org/10.1016/0749-6036(85)90111-9 (1985).
- Band parameters for III–V compound semiconductors and their alloys. \JournalTitleJournal of Applied Physics 89, 5815–5875, DOI: 10.1063/1.1368156 (2001).
- Varshni, Y. Temperature dependence of the energy gap in semiconductors. \JournalTitlePhysica 34, 149–154, DOI: https://doi.org/10.1016/0031-8914(67)90062-6 (1967).
- Lourenço, S. A. et al. Temperature dependence of optical transitions in AlGaAs. \JournalTitleJournal of Applied Physics 89, 6159–6164, DOI: 10.1063/1.1367875 (2001).
- Colocci, M. et al. Temperature dependence of exciton lifetimes in gaas/algaas quantum well structures. \JournalTitleEurophysics Letters 12, 417, DOI: 10.1209/0295-5075/12/5/007 (1990).
- Ivanov, A. L. Quantum diffusion of dipole-oriented indirect excitons in coupled quantum wells. \JournalTitleEurophysics Letters 59, 586, DOI: 10.1209/epl/i2002-00144-3 (2002).
- Spectroscopy of Semiconductor Microstructures, vol. 206 of NATO ASI Series (Springer US, Boston, MA, 1989).
- Direct measurement of exciton diffusion in quantum wells. \JournalTitleSolid-State Electronics 40, 725–728, DOI: https://doi.org/10.1016/0038-1101(95)00351-7 (1996). Proceedings of the Seventh International Conference on Modulated Semiconductor Structures.
- Smith, L. M. et al. Phonon-wind-driven transport of photoexcited carriers in a semiconductor quantum well. \JournalTitlePhys. Rev. B 39, 1862–1870, DOI: 10.1103/PhysRevB.39.1862 (1989).
- Energy relaxation and transport of indirect excitons in alas/gaas coupled quantum wells in magnetic field. \JournalTitleJournal of Experimental and Theoretical Physics 87, 608–611, DOI: 10.1134/1.558700 (1998).
- Luminescence dynamics in type-ii gaas/alas superlattices near the type-i to type-ii crossover. \JournalTitlePhys. Rev. B 54, 14589–14594, DOI: 10.1103/PhysRevB.54.14589 (1996).
- Baranowski, M. et al. Carrier dynamics between delocalized and localized states in type-II GaAsSb/GaAs quantum wells. \JournalTitleApplied Physics Letters 98, 061910, DOI: 10.1063/1.3548544 (2011).
- Mazuz-Harpaz, Y. et al. Radiative lifetimes of dipolar excitons in double quantum wells. \JournalTitlePhys. Rev. B 95, 155302, DOI: 10.1103/PhysRevB.95.155302 (2017).
- Pieczarka, M. et al. Lateral carrier diffusion in InGaAs/GaAs coupled quantum dot-quantum well system. \JournalTitleApplied Physics Letters 110, 221104, DOI: 10.1063/1.4984747 (2017).
- Rudno-Rudziński, W. et al. Carrier diffusion as a measure of carrier/exciton transfer rate in InAs/InGaAsP/InP hybrid quantum dot–quantum well structures emitting at telecom spectral range. \JournalTitleApplied Physics Letters 112, 051103, DOI: 10.1063/1.5016436 (2018).
- Luttinger, J. M. Quantum theory of cyclotron resonance in semiconductors: General theory. \JournalTitlePhys. Rev. 102, 1030–1041, DOI: 10.1103/PhysRev.102.1030 (1956).
- Kubisa, M. et al. Photoluminescence investigations of two-dimensional hole landau levels in p-type single alxga1−xAs/GaAssubscriptal𝑥subscriptga1𝑥AsGaAs{\mathrm{al}}_{x}{\mathrm{ga}}_{1-x}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}% \mathrm{A}\mathrm{s}roman_al start_POSTSUBSCRIPT italic_x end_POSTSUBSCRIPT roman_ga start_POSTSUBSCRIPT 1 - italic_x end_POSTSUBSCRIPT roman_As / roman_GaAs heterostructures. \JournalTitlePhys. Rev. B 67, 035305, DOI: 10.1103/PhysRevB.67.035305 (2003).
Paper Prompts
Sign up for free to create and run prompts on this paper using GPT-5.
Top Community Prompts
Collections
Sign up for free to add this paper to one or more collections.