Power loss by a two-dimensional hole gas in a Si/Si0.8Ge0.2 heterostructure over a wide temperature range.

The average power loss of two-dimensional hole gas (2DHG) due to acoustic and optical phonons is calculated in a Si/Si0.8Ge0.2 heterostructure over a wide temperature range. The power loss of 2DHG due to acoustic phonons via deformation potential coupling and Pekar mechanism is calculated taking account of temperature dependent screening. The hole-acoustic phonon coupling is found to dominate hole power loss for Tc<70 K. The experimental power loss data for Tc<2 K is accounted for by Pekar mechanism and the data for 2 K<Tc<4.2 K is explained by the total contribution of these two mechanisms. Pekar mechanism is found to be important in these systems at very low Tc. Power loss calculation due to nonpolar optical phonons is carried out taking account of hot phonon effect and it is important and dominant for Tc>70 K. Hot phonon effect is found to reduce the power loss of 2DHG by a factor of about 1.5. The power loss calculations are carried out for different carrier concentrations and compared with those in GaAlAs/GaAs heterostructures. [ABSTRACT FROM AUTHOR]