30 Jun 2015

PVEducation.org: A resource for teaching solid-state chemistry and photovoltaics

Web Resources and Apps

Submitted by Kate Plass, Franklin & Marshall College
Categories
Corequisites: 
Prerequisites: 
Course Level: 
Description: 

This is a website that teaches students about various aspects of pn-junction photovoltaics, from basics about solar illumination, to solid state chemistry, to PV module design. There are numerous animations demonstrating facets of solid-state chemistry and light absorption. Here I will describe how I have used sections 3.1 Basics and 3.2 Generation in Inorganic Chemistry in the context of a specific laboratory application, but the site could have many more uses.

Learning Goals: 

- Students should be able to define valence band, conduction band, band gap, and charge carriers.
- Students should be able to interpret the light absorption spectra of semiconductors in terms of band theory.
- Students should be able to calculate the band gap of a semiconductor from the light absorption spectrum.

Implementation Notes: 

I have used this in different ways in "Inorganic Chemistry", a half-semester elective "Chemistry of Solar Energy Conversion" and in upper level "Materials Chemistry" courses.

In the context of interpreting absorption spectra of semiconductors, the following three animations were used:
3.1 Basics/Band gap (http://pveducation.org/pvcdrom/pn-junction/band-gap) was shown to students to introduce the idea of bands and the necessary terminology.
3.2 Generation/Absorption of light (http://pveducation.org/pvcdrom/pn-junction/absorption-of-light) was shown to facilitate discussion of the relationship between the band gap energy and which energy photons are absorbed, allowing prediction of what the absorption spectrum would look like.
3.2 Generation/Absorption coefficient (http://pveducation.org/pvcdrom/pn-junction/absorption-coefficient) was used to illustrate spectra and how it can be used to calculate band gap.

Time Required: 
10 min
Evaluation
Evaluation Methods: 

Students wrote laboratory reports in which they were asked to interpret spectra of ZnO nanoparticles of different sizes. The success of this particular set of learning objects was assessed by examining the degree to which students described spectra using appropriate terminology and correctly calculated band gap values and compared spectra for different size particles.

Evaluation Results: 

Students described spectra and calculated band gaps well, though no quantitative data was collected on this specific aspect of the report.

Creative Commons License: 
Creative Commons Licence

Comments

Was the ZnO nanopartticle lab something you developed? If so it would look great on VIPEr.

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