Electron-beam induced degradation in CdTe photovoltaics

We used electron beam induced current (EBIC) to measure degradation of CdTe photovoltaic cells. We have observed that: (i) the EBIC signal shows a con siderable, continuous degradation depending on the electron-beam current, s can area, energy, and sample treatment; (ii) the characteristic degradation time fluctuates between different spots on the same sample; and (iii) grai n boundary regions are the most effective collectors of the electron-beam g enerated charge carriers. Our phenomenological model relates the observed d egradation to defects caused by the electron-beam generated electrons and h oles. (C) 2000 American Institute of Physics. [S0021-8979(00)04416-9].