@InProceedings{PirralhoPeSoOkFoRaAb:2017:TrNePo,
author = "Pirralho, Mar{\'{\i}}lia de J. P. and Peres, Marcelo L. and
Soares, Dem{\'e}trio A. W. and Okasaki, Anderson K. and Fornari,
Celso Israel and Rappl, Paulo Henrique de Oliveira and Abramof,
Eduardo",
affiliation = "{} and {} and {} and {} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Transition from negative to positive photoconductivity in p-type
Pb1-xEuxTe films",
booktitle = "Resumos...",
year = "2017",
organization = "Brazilian Workshop on Semiconductor Physics, 18. (BWSP)",
abstract = "The phenomenon of photoconductivity has been used as an important
tool to investigate the presence of additional states within the
band structure of semiconductors [1] and has provided basic
knowledge that allowed the development of photodetector and sensor
devices along the last decades [2]. We investigated the
photoconductivity effect in p-type Pb1-xEuxTe films for x=0.01,
0.02, 0.03, 0.05 and 0.06 at T=300K. The measurements revealed a
clear transition from negative to positive photoconductivity as
the Eu content x is increased at room temperature. This transition
is related to the metal-insulator transition that occurs due to
the disorder originated from the introduction of Eu atoms and it
is an Anderson transition. Our investigation found that, from the
potential application point of view, the sample x=0.06 is more
suitable, i.e. it presents an almost noise free signal and the
higher photoconductivity amplitude response observed. The
photoconductive for the sample with x=0.06 was further
investigated in the temperature range of 77 300K and,
surprisingly, multiple additional transitions were observed with
amplitudes that reached around 200 times the original value before
illumination. We show that this anomalous behavior is a
consequence of the generation and recombination rates between the
bands and the 4f level and a defect level located inside the
bandgap. The main goal of this work is to make a prospective study
of NPC effect in p-type Pb1-xEuxTe films in both sides of the
metal-insulator transition aiming to possible new applications in
the development of photonic devices that operate from low
temperature up to room temperature. Acknowledgments: The authors
would like to acknowledge CAPES and FAPEMIG for support.
References: [1] M. M. Furchi et al, Nano Letters 14, 6165-6170
(2014); [2] R. Jaramillo et al, Jour. Appl. Phys. 119, 035101
(2016).",
conference-location = "Maresias, SP",
conference-year = "14-18 ago.",
language = "en",
urlaccessdate = "28 abr. 2024"
}