Electron temperatures in Si-MOSFETs: Determination from broadband far infrared emission

Electron temperatures in n-inversion layers of (1 0 0)-Si-MOSFETs are measured as a function of the electric field by analysing the absolute intensities of the broadband thermal far infrared emission from the two-dimensional electron gas. The electron heating δ T is proportional to the square root of the input power in the experimentally accessible range of 2 K ⩽ Δ T ⩽ 30 K at 4.2 K lattice temperature. Data in the whole electron concentration range (1 to 5 x 10 ¹² cm ^-2) are presented resulting in a concentration-independent heating of ΔT/(eμE ²) ^{1}/{2} = ( 0.7 ± 0.2) x 10 ^-2Ks {1}/{2} ( eV) ^{- {1}/{2}}. An increase of the electron heating (especially at high electron concentrations) is observed when a negative substrate bias is applied.