Anomalous temperature dependence of the energy gap of AgGaS2
1973; Elsevier BV; Volume: 13; Issue: 11 Linguagem: Alemão
10.1016/0038-1098(73)90750-3
ISSN1879-2766
AutoresPhil Won Yu, W. J. Anderson, Yeonju Park,
Tópico(s)Advanced Thermoelectric Materials and Devices
ResumoThe lowest energy gap Eg of AgGaS2 in the temperature range from 4.2 to 300° K was determined from the reflectivity, photoluminescence and absorption measurements. Below ∼ 80° K the temperature coefficient of the energy gap is +6 × 10-5 eV/°K. Above ∼80° K the sign of the coefficient reverses and the value is -1.8 × 10-4 eV/°K. The positive value is explained with the lattice dilation effect being the dominant mechanism for the energy gap variation at lower temperatures than ∼80°K. Das kleinste Energy Gap von AgGaS2 wurde im Bereich von 4.2 bis 300° K mittels Reflektions-Photoluminscenz-und Absorptions-Messungen bestimmt. Unterhalb ∼ 80° K betragt der Temperaturkoeffizient von Eg +6 × 10-5 eV/°K. Überhalb ∼ 80° K wechselt das Vorzeichen des Koeffizienten und beträgt -1.8 × 10-4 eV/°K. Der positive Betrag kann durch den dominierenden Mechanismus der Gitter Dilation unterhalb ∼ 80° K erklärt werden.
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