The characteristics of infrared photosensitivity for injection photodiodes on p-InSb base were investigated. It is shown that as a result of electron irradiation at electron energy E = 225 MeV and integral dose Ô = 10 14 sm-2 the carrier lifetime practically does not change. The change of diodes parameters corresponds to the scheme for the formation of Frenkel defects in p-InSb: shallow donors — interstitial site In and Sb, shallow acceptor — Sb-vacancy, deep donor — In-vacancy. The threshold

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... am of light-irradiation for the dio-des practically does not change. Practically repeating the variation of dark VCC before irradiation, the graphs I(V) for IPhD and PhR as the result of irradiation were shifted differently. After irradiation the value of holes concentration p for the given IPhD and PhR decreased from 5·10 12 up to 3·10 12 cm-3 , i. e. velocity of holes removal was Dp/Ô = 2·10 —2 cm-1. The electron mobility m n changed from 2·10 5 up to 10 5 cm 2 /V·s, the mobility of the holes m p changed from 5·10 3 up to 2.8·10 3 cm 2 /V·s. The decrease of the difference concentrations of shallow acceptors and donors (N aN d) with velocity () Ô a d N N D-= 1.8·10 —2 cm-1 as the result of irradiation took place. Simultaneously the concentration of deep acceptor levels with activation energy E c — 0.05 eV is observed to increase with approximately the same velocity. This corresponds to data for p-InSb-resistors [4]. In this work it was shown that concentration of recombination levels does not The injection photodiodes (IPhD) on the base of p-InSb, doped by germanium, with heavy holes concentration p 0 = 10 12 ...10 13 sm-3 were studied. The technology of the samples production was described in [1]. The length of the dio-des base was d = 0.5...5 mm. The properties of the similar photo resistors (PhR) were studied simultaneously. The measurements of the volt-current characteristics (VCC) and photosensiti-vity were executed at the temperature T = 77 K and below. The Hall constant and electrical conductivity were measured within the temperature range T = 55...300 K to determine the material parameters. The lifetimes of charge carriers were determined by measurements in photoconductiv-ity and photo magnetic effects. The samples were irradiated by the electrons with energy E = 2. 5 MeV. The integral doses of the irradiation were Ô = 10 14 cm-2. The p-n-conversion of InSb-conductivity, as in the case under the greater doses [2], at such doses did not yet occur. The temperature of the samples in process of irradiation was T ≥ 300 K. The VCC for one in the IPhD with d = 0.5 mm and the equivalent PhR are presented in Fig. 1. They are linear in wide range of voltages. The direct branch of the VCC of IPhD has several sections of current dependence on voltage: the ohmic in the area of low currents, practically coincided with VCC for photo resistor; the super linear section (I ~ V n , where n = 2...3). The super exponential section, the area of negative differential resistance and the section of the strong current increase after switching follow herein. Only two first sections (I = qp 0 m p V/d) and (I = (9/8)qm n m p p 0 t n V 2 /d 3) are shown in Fig. 1, since namely they in this case present the most interest with standpoint of injection amplification. In the main ways, VÑC of the diodes corresponds to the work data [3], in which the presence of S-characteristics is explained on the base of the injection breakdown theory for high-resistance compensated semiconductors in suggestion that recombination occurs through two independent levels with energy E 1 = E v + 0.071 eV and E 2 = E v + 0.11 eV. Fig. 1. The dark I-V-characteristics of the diode (1, 1¢) and resistor (2, 2¢), the dependence I ph (V) for IPhD (3, 3¢) and PhR (4, 4¢) before and after (the figures with touch) the irradiation. T = 60 K, l = 10.6 mm © Sh. D. Kurmashev, I. M. Vikulin, S. N. Nikiforov, 2006