Open AccessИсследование временной динамики фотовозбужденных носителей заряда в сверхрешетках In-=SUB=-0.53-=/SUB=-Ga-=SUB=-0.47-=/SUB=-As/In-=SUB=-0.52-=/SUB=-Al-=SUB=-0.48-=/SUB=-As при воздействии фемтосекундными лазерными импульсами
Author(s) -
Д. С. Пономарев,
Р. А. Хабибуллин,
А. Н. Клочков,
А.Э. Ячменев,
А. С. Бугаев,
Д.И. Хусяинов,
А.М. Буряков,
Vladislav Bilyk,
Е. Д. Мишина
Publication year - 2018
Publication title -
fizika i tehnika poluprovodnikov
Language(s) - English
Resource type - Journals
eISSN - 1726-7315
pISSN - 0015-3222
DOI - 10.21883/ftp.2018.07.46042.8625
Subject(s) - charge carrier , electron , trapping , excitation , doping , wavelength , superlattice , materials science , substrate (aquarium) , carrier lifetime , atomic physics , analytical chemistry (journal) , chemistry , silicon , optoelectronics , physics , ecology , oceanography , chromatography , quantum mechanics , biology , geology
The results of experimental studies of the time dynamics of photoexcited charge carriers in In_0.53Ga_0.47As/In_0.52Al_0.48As superlattices grown by molecular-beam epitaxy on a GaAs substrate with a metamorphic buffer are reported. On the basis of the results of the numerical simulation of band diagrams, the optimal thickness of the In_0.52Al_0.48As barrier layer (4 nm) is chosen. At this thickness, the electron wave functions in In_0.53Ga_0.47As substantially overlap the In_0.52Al_0.48As barriers. This makes it possible to attain a short lifetime of photoexcited charge carriers (τ ~ 3.4 ps) at the wavelength λ = 800 nm and the pumping power 50 mW without doping of the In_0.53Ga_0.47As layer with beryllium. It is shown that an increase in the wavelength to λ = 930 nm (at the same pumping power) yields a decrease in the lifetime of photoexcited charge carriers to τ ~ 2 ps. This effect is attributed to an increase in the capture cross section of trapping states for electrons with lower energies and to a decrease in the occupancy of traps at lower excitation densities.