Altermatt Lecture:   The PV Principle


1.1:  Introduction

To understand and improve solar cells, it is helpful to start with their underlying principle. In this lesson, you will learn

  • to understand the photovoltaic principle,
  • the minimum requirements to have photovoltaic action of light,
  • how to apply the PV principle to a semiconductor such as silicon,
  • which mechanisms cause the voltage and the electric current to be generated by sunlight, and
  • how to understand the cell's output parameters.

And if you are familiar with thermodynamics, listen to the interview with our starring guest, Peter Würfel, who write the famous book "Physics of Solar Cells: From Basic Principles to Advanced Concepts" [1]. He explains the PV principle from a thermodynamic point of view.

Other outstanding introductions are those given by

  • Martin Green, "Solar Cells: Operating Principles, Technology and System Applications" [2];
  • Jenny Nelson, "Physics of Solar Cells" [3]; and
  • Christiana Honsberg and Stuart Bowden, PVCDROM.

Your learning is considerably more efficient if you do more than reading the following pages. For most people, it is efficient to

Output power from a solar cell

Figure: The classical electrical output from a solar cell, plotted as current density against voltage.

  • shortly summarize the main thought (optimally containing a keyword), to
  • attach a picture to it (which optimally reflects the dynamics of the subject), and to
  • go through your summary the next day, in a week's time, and in a month's time.

To do this, you may download an MSword document, containing the subject titles and the pictures. Saving time by "only reading it" usually does not pay off the extra amount of time needed later for recovering forgotten knowledge.

Some pages contains advanced material. These are marked with an asterisk.


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