Gel Probe Photocurrent Measurement Device

Invention Summary:

Photocurrent action spectra or external quantum efficiency (EQE) measurement of semiconductor thin films is an important parameter for solar cell development. Values higher than 80% photon to electron conversion efficiency over a broad range of wavelengths are necessary (but not sufficient) condition for the development of highly efficient solar cells. However, this measurement is usually performed on the actual solar cells, meaning the knowledge occurs once the final device is assembled which makes this important measurement burdensome and time consuming. It would be very desirable to gain such knowledge early on in construction of the cell by having a simple probe measurement of the photoactive semiconductor, as this would save cost and research time.

Researchers at Rutgers University have developed a Gel Probe Photocurrent Device that can measure external quantum efficiency of photoactive film directly without having to coat a transparent conducting oxide layer or using metal evaporation for contacts on photovoltaic devices. This invention consists of an optical reflection probe with a copper tip and Teflon© insulating spacer containing a gel electrolyte which can be applied to the surface of semiconductors in order to collect photocurrent useful for the measurement of external photocurrent quantum efficiency.

Upon excitation of the material’s bandgap, holes or electrons react with the gel electrolyte, causing a photocurrent, which is collected by the metal contact surrounding the probe. This method and device is very effective in characterizing the impact of blocking layers, or semiconductor preparation conditions and thickness on the photocurrent efficiency.

Market Application:

Inorganic Solar Cell development and manufacturing.


Ability to measure External Quantum Efficiency at early stage of cell construction.

Intellectual Property & Development Status:

Patent pending. Dr. DuPasquier has tested a prototype device on Polycrystalline Si and Cu2O.

Rutgers ID: 2009-074
Physical Sciences
Zolt Pukanecz
Aurelien Du Pasquier
Solar Cells