Articolo in rivista, 2016, ENG, 10.1088/0268-1242/31/12/12LT01

On the relation between deep level compensation, resistivity and electric field in semi-insulating CdTe: Cl radiation detectors

Cola, Adriano; Farella, Isabella; Pousset, Jeremy; Valletta, Antonio

CNR IMM; CNR IMM

A compensation model for semi-insulating CdTe: Cl based on a single dominant deep level 0.725 eV above the valence band is proposed. The model is corroborated by experimental evidence: resistivity measurements as a function of temperature on bulk crystals and stationary electric field distributions in Ohmic/Schottky radiation detectors, obtained by the Pockels effect. The latter are in close agreement with the numerical solutions of transport equations when considering the deep centre concentration in the range 2 - 4 x 10(12) cm(-3), and a compensation ratio R = 2.1, this one being consistent with an original ambipolar analysis of resistivity. More generally, the approach elucidates the role of electrical contacts and deep levels in controlling the electric fields in devices based on compensated materials.

Semiconductor science and technology (Print) 31 (12), pp. 1–5

Keywords

CdTe, x-ray detectors, deep levels, electrical compensation, Pockels effect

CNR authors

Farella Isabella, Cola Adriano, Valletta Antonio

CNR institutes