Solar Energy Market to Advance Further as a Team Creates a Method Suggesting Reasons why Cadtel Performance remains to be Subpar
Posted On April 16, 2022
Solar energy is nearly entirely generated via panels or modules made of silicon-based light-absorbing cells. Silicon is the general standard because it is dependable and affordable, with a well-understood structure and function.
However, silicon cell modules are only around 20% efficient at converting sunlight to power. Further, their manufacture is both expensive and difficult. Different materials or combinations of materials are used in efforts to reduce technology costs relative to yield. Cadmium, selenium, and telluride, abbreviated as CdSeTe ("CadTel" informally), is one such combination. However, current CdSeTe devices have poorly understood voltage deficiencies that jeopardize their performance.
A research team has unveiled a method for why CdSeTe solar cell voltages aren't higher. The team was able to identify a technique that works. This is a huge contribution to the Solar Energy Market as the process could help pave the path for better performance.
They also learned that the principal mechanism limiting voltage is not necessarily tied to faults inside the bulk of the cell. It might not even be at the interfaces between different materials constituting the cell.
The team explained that in the CadTel community, that's usually what's assumed. Instead, it's a problem with selectivity. This occurs when electrons in a cell travel in the wrong direction and cancel each other.
A dip in the cell's internal and exterior voltages corresponds to selectivity losses. The internal voltage is a measure of how imperfections in the absorber's bulk and at its interfaces reduce voltage below a thermodynamically optimal limit. Internal voltage removes losses due to non-ideal behavior in the semipermeable membranes. This sandwiches or wraps the cell absorber and directs electron flow in and out of the cell to generate an electric current.
Different devices exhibit different sorts of voltage losses. So, the team's new research demonstrates that things are more complicated than previously thought. Hence, more exact accounting is required. As a result, the ability to measure internal voltage via ERE is a significant advancement.
The team plans to use the measurement technique in the future to assist in developing solar cells made from other advanced materials. These include perovskites, a class of chemicals that absorb light from a different part of the electromagnetic spectrum than silicon.
The ERE methodology works through glass. This is why solar cells already packaged inside commercial modules can be examined in ways that a common method known as QSSPC (Quasi-Steady-State Photoconductance) cannot. The findings of the study will also be applied to ordinary silicon solar cells.