The super-efficient bifacial n-PERT cell development has magnified the power-generation potential of solar cells.
The cell design has been facilitated by Imec, an international world research and nano-electronics and digital technology organisation. The bifacial solar cells are capable of capturing light on both the front and the back sides and this is actualised due to the featuring of a transparent backside and comparable front-and-back contact schemes. This helps in drawing benefits from a variety of sources of light which may not be necessarily direct. The indirect light is inclusive of the light reflected from ground and buildings, the diffused light from sunrise and sunset light, and during overcast days. The solar cells based on an industrially compatible process has realised a record-setting front side conversion efficiency of around 22.8%.
According to Imec, the tests indicate that such bifacial cells over a course of their lifetime could generate 10 to 40% more electricity than the traditional monofacial cells. This would depend on their bifaciality, the reflection, the PV installation properties, and the location. This could result in an estimated levelised cost of electricity (LCOE) reduction for photovoltaic (PV) installations of 10 up to 30%.
Imec’s bifacial n-PERT cells are thin and narrow (< 20 µm) nickel-silver (Ni/Ag) plated fingers on both the n+ and p+ side of the cell. A patented process helped the fabrication of the cells’ contacts which included the simultaneous plating both cell sides. The cell plating is reportedly performed at cassette level and has no need for an electrical contact to be made to the substrates. This would result in a solar cell batch having an average conversion efficiency of around 22.4% and the best cell demonstrating a record efficiency of about 22.8%.
These outcomes have been reportedly measured internally and based on an ISE CalLab calibrated reference cell and with a GridTOUCH system under the standard test conditions by using front side illumination and a non-reflective chuck.