Research @ the Solar Energy Group

Photovoltaics Research

In common with all heat engines, fundamental physical processes place a limit on the efficiency of photovoltaic devices. In a traditional solar cell, the limiting efficiency is usually a function of the band-gap of the absorbing material, giving rise to the "Shockley-Queisser" [1] efficiency limit shown as a curve in figure 1, the points represent the best experimental single band-gap cells fabricated to date. The photovoltaic activities in the School of Physics at Sydney University are mainly concerned with high-performance photovoltaic devices and systems, the majority of which aim to break the Shockley-Queisser efficiency limit.

Figure 1. Limiting efficiency curve for a single band-gap solar cell under AM1.5 illumination. The points represent the best experimental single band-gap cells fabricated to date.

A broad range of photovoltaic technologies are under investigation, spanning fundamental cell research to system performance under high concentration solar flux. Three broad experimental techniques are employed by the group:

1. Cell characterisation under high concentration solar flux using the group's dish concentrator [LINK HERE].
2. Semiconductor defect studies using transient capacitance spectroscopy.
3. Luminescence spectroscopy of new semiconductor materials suitable for high performance photovoltaic devices.

The chart shown in figure 2 shows the relationship between various cell technologies and the experimental strategies.

Figure 2. Chart showing the relationship between various cell technologies and the experimental strategies.