Investigation of Vacancy Defect in InP Crystal by Positron Lifetime

Positron lifetime measurements were carried out on liquid-encapsulated Czochralski-grown undoped InP samples sliced from middle of ingots over the temperature range of 10 ∼ 300 K. At 70 K, the spectra were measured in darkness, under illumination of infrared LED, and while illumination off respectively on one of samples. The measurements at low temperature revealed different concentration of hydrogen indium vacancy complex VIn H4 in these samples. A relatively higher concentration of VInH4 existing in that grown from P-rich undoped InP melts could be shown. The increase of resistivity of these samples could be speculated when temperature was low enough.