Implementation and quantification of scanning transmission EBIC experiments for measuring nanometer diffusion lengths in manganite-titanite p-n heterojunctions
by Patrick Peretzki
Date of Examination:2018-12-19
Date of issue:2019-01-08
Advisor:Prof. Dr. Michael Seibt
Referee:Prof. Dr. Michael Seibt
Referee:Prof. Dr. Christian Jooß
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Description:Dissertation Patrick Peretzki
Abstract
English
The scanning transmission electron beam induced current (STEBIC) approach to measure charge carrier diffusion lengths in the nanometer range in 3rd generation photovoltaics devices is presented, evaluated and applied to the manganite-titanite p-n heterojunction PCMO-STNO. Quantitative measurement and evaluation of the room temperature diffusion length of PCMO and STNO are enabled by varying electron beam acceleration voltage and sample thickness, using scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM) instrumentation. Low temperature experiments confirm an expected increased PCMO diffusion length. Finally, two promising simulation methods for STEBIC data as well as first studies of the PCMO-STNO heterojunction electric potential by off-axis electron holography are presented and discussed.
Keywords: Electron microscopy; EBIC; Photovoltaics; Nanoscience; Diffusion length; Manganite