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We have investigated photoconductivity and mobility in TlBr from –30 ΩC up to +20 ΩC, where the ionic conductivity is pronounced. Mobility‐related conductivity maximum superimposed on an interband‐generation conductivity growth was observed. It could be caused by the recharge of the scattering centre at about 1.65 eV. From spectral dependencies defect‐related transitions at 0.55; 0.83, 1.1; 1.32 and 1.65 eV were identified, being dependent on sample prehistory, i.e., its excitation by light and/or voltage. The transient photocurrent kinetics has demonstrated a complex behaviour that could be explained by the combined influence of electron generation/recombination processes superimposed upon the ionic conductivity. The thermally activated ionic conductivity was still effective at –20 ΩC. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

In this work study of photoluminescence (PL) spectra in the Er‐doped glasses of the AgGaS2‐GeS2 system is presented. Emission spectra of the glasses at T ≈ 292 K, excited by light with λex ≈ 980 nm and λex ≈ 532 nm are described well by transitions in the 4f‐shell of Er3+ ions. Spectral curves of the emission can be deconvoluted into four Gaussian components. Er atoms are localized both in the glass matrix and (with increased concentration) around large structural damages (heterogeneities) which are drains for them. This causes broadening of the emission bands of Er3+ ions that are localized around heterogeneities. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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We had observed the persistent photoconductivity in TlBr. The long lasting current relaxations took place after the band-to-band light excitation at the temperatures below about 200 K. It was demonstrated by the thermally stimulated current method that this phenomenon is related to the trapping states with the thermal activation energy of 0.08 -0.12 eV. Moreover, upon filling of the traps the enhanced photoconductivity was induced that could be thermally quenched above about 180 K. The quenching of the photoconductivity is initiated by the emptying of the trapping states with the activation energy of 0.63 -0.65 eV.Keywords: TlBr / persistent photocurrent / enhanced photoconductivity / defects / traps / Es wurde eine persistente Photoleitfähigkeit in TlBr beobachtet. Die langzeitigen Strom-Relaxationen fanden auch nach der Band-zu-Band Lichtanregung bei Temperaturen unter 200 K statt. Bei der Anwendung der Methode des thermisch stimulierten Stroms wurde gezeigt, dass dieser Effekt durch Zustände mit thermischen Aktivierungsenergien von 0.08 -0.12 eV verursacht werdenkönnte. Darüber hinaus führte eine Füllung dieser Zustände zu der erhöhten Photoleitfähig-keit. Dieser Zustand konnte bei Temperaturen über 180 K thermisch gelöscht werden. Die Lö-schung der Photoleitfähigkeit erfolgte bei der Entleerung der Zustände mit Aktivierungsenergien von 0.63 -0.65 eV.