Room-temperature irradiation of p-type Silicon

Transient capacitance spectroscopy is used to study majority and minority traps introduced in pulled and float-zone boron-doped silicon, after 1.5 MeV electron irradiation at room temperature. In addition to familiar levels attributed to the positive charge state of the divacancy, the carbon interstitial, and the carbon-related defects, some other traps previously reported in solar cells are detected. In pulled silicon the minority trap Ec – 0.26 eV is studied and the results favour its attribution to the (Bi–Oi) complex. Some differences exist between these results and those already reported by other authors for p-type silicon. In particular, the peak normally attributed to the carbon interstitial displays different annealing behavour between the float-zone and the pulled material.