ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Minority-carrier electron-diffusion coefficients and lifetimes have been measured in heavily doped p-type GaAs using the zero-field time-of-flight (ZFTOF) technique. The materials studied included C-doped GaAs grown by molecular-beam epitaxy (MBE) using graphite as the dopant source, C-doped GaAs grown by metalorganic chemical-vapor deposition (MOCVD) using CCl4 as the dopant source, and Be-doped GaAs grown by MBE. Room-temperature photoluminescence intensity measurements were made on the structures and the results are compared with ZFTOF measurements of lifetime. The graphite-doped material (p∼1019 cm−3) exhibited diffusion lengths of less than 1000 A(ring). MOCVD-grown C-doped GaAs, which was optimized by adjusting the growth conditions to maximize the room-temperature photoluminescence intensity, had diffusion lengths comparable to those measured in Be-doped GaAs for hole concentrations of 1×1019 and 5×1019 cm−3. Comparison of photoluminescence intensities also suggests that addition of In to very heavily doped MOCVD-grown GaAs (p(approximately-greater-than)1020 cm−3) to eliminate the lattice mismatch with respect to the substrate does not result in an improvement in lifetime.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.353991
