Near Infrared Absorption in Phosphorus DopedP-Type ZnTe

Near infrared absorption in p -type ZnTe doped with phosphorus has been measured between 15°K and 500°K and the results are compared with theory. The absorption band was observed at about 1.2 µm (1.0 eV). From its dependence on temperature and on impurity concentration and from its behavior for the sample counter-doped with indium, the band is attributed to the transition from the split off valence bands to the shallow acceptor states of phosphorus and to the top valence bands. The essential features are in good agreement with theoretical results. The radius of the acceptor state and the spin orbit energy at the point are determined to be 10 Å and 0.99 eV, respectively, and the heavy hole mass parameter is estimated to be between 1.2 and 1.8 m , assuming the split off band mass parameter of 0.31 m , as obtained theoretically by one of the authors.