Question: What do you use to measure a solar cell?

Matt Carnie answered on 17 Jun 2013:

We use lots of instruments to measure our solar cells but the most important is our solar simulator. It’s basically a very expensive light bulb in a box which matches the Sun’s spectrum and power exactly. We know the power of the lamp and we measure the electrical power given by the cell. The efficiency of the cell is simply the power output of the cell divided by the power input by the lamp.