1972/03/01 by Kōzō Osamura, Yôtaro Murakami · 2 citations
Physics and Astronomy · Engineering · Chemistry · #Semiconductor Quantum Structures and Devices #Advanced Semiconductor Detectors and Materials #Semiconductor materials and interfaces #Free carrier absorption #Impurity #Absorption cross section #Absorption (acoustics) #Scattering #Analytical Chemistry (journal) #Effective mass (spring–mass system) #Infrared #Chemistry #Materials science #Free carrier #Atomic physics #Ionization #Phonon #Cross section (physics) #Optics #Semiconductor #Condensed matter physics #Optoelectronics #Physics #Ion
paper · doi:10.1143/jjap.11.365
openalex publication_date 1972/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The infrared absorption between 400 and 4,000 cm -1 is measured as a function of carrier concentration for n -type GaAs at three different temperatures of 90°, 300° and 450K. The absorption in the 800 to 2,000 cm -1 region is only due to the optical transition of free carriers. The free carrier absorptions arising from three scattering sources, i.e. acoustic and optical phonons, and ionized impurities, are numerically evaluated in the infrared region. At a constant wave number, 1,000 cm -1 , a comparison of the theoretical cross section with the experimental value is performed and the degree of compensation of impurities ( N imp / N e ) for each sample is graphically determined using the total photon capture cross section vs. carrier concentration chart. The numerical results of the wave number and temperature dependences of free carrier absorption are in good agreement with the experimental data in the wide range of carrier concentrations from 1 × 10 16 to 1 × 10 18 cm -3 . A relatively sharp peak is detected at =3,200 cm -1 at 90K. The absorption is suggested to occur by a transition from a deep impurity level (0.4 eV) to the conduction band.