Helen Par

11 Questions 6 Answers 0 Followers

Questions related from Helen Par

Can the n-type buffer layer (ETL) in a thin film solar cell have a high carrier concentration?

When choosing an n-type buffer layer or electron transport layer (ETL), is there a limit to how high its carrier concentration should be, relative to the absorber layer and the window layer? For...

04 April 2019 4,863 7 View

Why does improving interfacial recombination improves VOC in solar cells?

Many literature reports on the increase in VOC when interfacial recombination is being suppressed, with little change to JSC and FF. How can we explain this strong relation between VOC and...

04 April 2019 8,151 6 View

Detecting Oxygen Vacancies using the O-1s region of XPS?

Hello everyone! If an oxygen vacancy is the lack of an oxygen in a site in the lattice, what is a possible explanation for the ability to probe the presence/quantity of oxygen vacancies in an...

04 April 2019 5,962 13 View

Whats the reason for Increasing Oxygen Vacancies in Metal Oxide Thin Films with Increasing Deposition Temperature?

What can be a possible explanation for observing increasing oxygen vacancies in a metal oxide film (eg: Cu2O) deposited using ALD or CVD when the deposition temperature is increased? As I...

04 April 2019 8,552 5 View

Using Sentaurus, how can we simulate the time-resolved photoluminescence (TRPL) decay curves in a solar cell?

Using Sentaurus, how can we simulate the time-resolved photoluminescence (TRPL) decay curves in a thin film material, say Silicon? Anyone kind enough to share the Sentaurus file for a similar...

08 August 2018 5,119 1 View

Does a stronger bandgap PL emission correlate to a longer TRPL lifetime?

Consider a case where 3 thin film samples have bandgap PL emission intensities 1, 2 and 3 and defect emission intensities 1, 1, and 1. (ie: The PL spectrum have been normalized to the defect...

08 August 2018 2,964 5 View

Is it possible for a dopant (such as Germanium) to turn SnO2 into an intrinsic material?

If a n-type semiconductor material SnO2 has a carrier concentration of 1E19 cm-3 (mainly due to oxygen vacancies), is it possible that doping it with an element with the same 4+ charge can reduce...

08 August 2018 1,874 3 View

How can we differentiate Sn2+ and Sn4+ from a thin film using XRD/PL/Raman/FTIR/RBS/UV-Vis?

I am trying to differentiate Sn2+ from Sn4+ in my SnO2 thin films and hopefully quantify the amounts as well. The thin film material can contain both Sn2+ and Sn4+ oxidation states. It is...

04 April 2018 4,877 5 View

How can oxygen be incorporated into SnS using ALD?

I have successfully deposited SnS thin films using ALD by alternating doses of a tin (ii) metal precursor gas with hydrogen sulphide gas. For some oxygen to be incorporated into the SnS material,...

04 April 2018 2,240 6 View

Single/Double Exponential Decays in Time Resolved Photoluminescence

In the time-resolved photoluminesence measurements of semiconductor materials, what causes single exponential decays and what causes double exponential decays?

07 July 2017 3,588 4 View

Is a Material of Low Quality if the PL emission from Defects are Stronger than Band to Band Transitions?

Lets say we have a room temperature PL spectrum. If an oxide material (eg: Cu2O) have very strong defect related PL emissions (O vacancies, Cu vacancies) and weak band-to-band PL emissions (but...

07 July 2017 2,208 3 View