Publication

Charge trapping effects in photovoltage measurements of (Ga,Mn)As

Jean-Philippe Ansermet, Simon Granville
2008
Journal Articles

Abstract

We report charge trapping effects in a ferromagnetic (Ga,Mn)As thin film observed during measurements of the photovoltage under inhomogeneous illumination conditions. Using a laser diode as the excitation source, the temperature-dependent response has been observed, with open-circuit voltages as high as -1.4V. The unexpectedly large and sharp temperature-de pendent responses are explained in terms of the excitation of photo-generated charges and their trapping in localised states, or separation of the charges across the film/substrate interface. The sharp features found in the signals suggest their possible use for studying localised trapping states in semiconductors using inhomogeneous illumination. (C) 2008 Elsevier B.V. All rights reserved.

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https://infoscience.epfl.ch/entities/publication/2c0b0eaa-487d-4b52-a13c-96e5093652b6

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Jean-Philippe Ansermet, Simon Granville
2008
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/2c0b0eaa-487d-4b52-a13c-96e5093652b6

About this result

Related concepts (23)

Laser diode

A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction. Driven by voltage, the doped p–n-transition allows for recombination of an electron with a hole. Due to the drop of the electron from a higher energy level to a lower one, radiation, in the form of an emitted photon is generated. This is spontaneous emission.

Thin film

A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many applications. A familiar example is the household mirror, which typically has a thin metal coating on the back of a sheet of glass to form a reflective interface. The process of silvering was once commonly used to produce mirrors, while more recently the metal layer is deposited using techniques such as sputtering.

Laser pointer

A laser pointer or laser pen is a small handheld device with a power source (usually a battery) and a laser diode emitting a very narrow coherent low-powered laser beam of visible light, intended to be used to highlight something of interest by illuminating it with a small bright spot of colored light. The small width of the beam and low power of typical laser pointers make the beam itself invisible in a clean atmosphere, only showing a point of light when striking an opaque surface.

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