Abstract:

A variational method combined with solving the force balance equation is adopted to investigate the influence of strain and hydrostatic pressure on electronic mobility in a strained wurtzite AlN/GaN heterojunction byconsidering the scattering of optical-phonons in a temperature ranges from 250 to 600 K. The effects of conductionband bending and an interface barrier are also considered in our calculation. The results show that electronic mobilitydecreases with increasing hydrostatic pressure when the electronic density varies from 1.0E12 to 6.5E2 cm–2. The strain at the heterojunction interface also reduces the electronic mobility, whereas the pressure influencebecomes weaker when strain is taken into account. The effect of strain and pressure becomes more obvious as temperatureincreases. The mobility first increases and then decreases significantly, whereas the strain and hydrostaticpressure reduce this trend as the electronic density increases at a given temperature (300 K). The results also indicatethat scattering from half space phonon modes in the channel side plays a dominant role in mobility.

Key words: hydrostatic pressure,  strained AlN/GaN heterojunction,  electronic mobility,  optical-phonon scattering