Café com Física

Helena Vieira Alberto: Quantitative study of structural distortions in the interface region of solar cells, using implanted positive muons

Portugal
Sala de Conferências (Departamento de Física FCTUC)

Sala de Conferências

Departamento de Física FCTUC

Universidade de Coimbra
Description

Positive muons can be used as local probes in solar cells to study the interface region between materials with n and p type conduction. Muons are implanted at different depths in the presence of an external magnetic field. The muon signal corresponds to the time evolution of the muon spin in the direction of the implantation beam . The signal amplitude decreases if the lattice around the muon stopping site suffers an increasing distortion, due to defects. Experimental results show that there is a defect region in the p material, near the interface, and the muon probe can be used to determine quantitatively which materials are more effective in reducing this region. This information is important for solar cells, since defects  act as electron-hole recombination centres, reducing the device efficiency.

Organized by

Paulo Brás, Paulo Silva, Jaime Silva