Observation of high mobility 2DHG with very high hole density in the modulation doped strained Ge quantum well at room temperature

Very high two-dimensional hole gas (2DHG) drift mobility of 3100 cm ² V ^-1 s ^-1 is obtained at extremely high density of 4.1×10 ¹² cm ^-2 in the modulation doped (MOD), 20 nm thick, strained Ge quantum well (QW) of SiGe heterostructure at room temperature. Obtained 2DHG mobility is higher and the carrier density is about eight times larger than those ever reported for SiGe MOD heterostructures. It is also noted that obtained values are not only the highest ones among 2DHG in the strained Ge QW but also larger than those of two-dimensional electron gas in the strained Si QW.