Effect of temperature on carrier transport and photoconductivity of Mn-doped FeS2 thin films

Abstract

Thin-film of Mn-doped iron disulfide (FeS2) has been prepared using the thermal evaporation method. This work reports the Hall measurements, temperature and light intensity-dependent photoconductivity, electrical transport mechanism, and photodetection properties of Mn-doped FeS2 thin film. The transient photoconductivity measurements of p-type Mn-doped FeS2 thin film show a consistent dependence upon temperature and light intensity. Charge transport mechanism was illustrated using different models. In region-I (303–393 ​K) deposited film followed the thermally activated transport mechanism. Nearest neighbour hopping (NNH) transport mechanism was followed by region-II (274–293 ​K), and Mott's variable range hopping (VRH) mechanism was dominant in region-III (108–273 ​K). The fabricated device resulted in higher photoconductivity due to collecting charge carriers through electrodes under light illumination. The results also revealed that Mn-doped thin film possessed good photoresponsivity (∼19 ​mA/W) as well as photo-detectivity (∼3.4 ​× ​1012 Jones) due to the occupation of localized states formed by Mn-doping. Light intensity-dependent photodetection properties suggested the potential for real-time photodetection applications.