Determination of the minority carrier diffusion length in compositionally graded Cu(In,Ga)Se2 solar cells using electron beam induced current

摘要

A method is proposed and tested which allows for the accurate determination of the carrierncollection efficiency and minority carrier diffusion length in Cuu0001In,Gau0002Se2 solar cells using energyndependent electron beam induced current. Gallium composition gradients across the film thicknessnintroduce quasielectric fields that are found to improve collection efficiency when they are locatedntoward the rear of the sample. The quasielectric fields are also shown to reduce the influence of backnsurface recombination. The strengths and limitations of this technique are discussed and comparednwith external quantum efficiency measurements. © 2010 American Institute of Physics.nu0003doi:10.1063/1.3291046