SPLTRAK Abstract Submission
Quantitative measurement of active dopant density distribution in black silicon solar cell using scanning nonlinear dielectric microscopy
Yasuo Cho1, Beniamino Iandolo2, Ole Hansen2
1Tohoku University, Sendai, Japan
/2Technical University of Denmark, Lyngby, Denmark

Black silicon (Si) is a nanostructured type of Si capable of near-total absorption of light. Therefore, the use of black Si can lead to highly efficient solar cells. The performance of Si solar cells is dependent on the active dopant carrier distribution in emitters.  The carrier distribution in black Si solar cells has been difficult to measure, and thus to optimize, due to the irregular, nano-scaled structure of the emitter.
In this paper, we investigated quantitatively the carrier distribution in a phosphorous (P) diffused black Si solar cell using scanning nonlinear dielectric microscopy (SNDM). As a reference, we measured the carrier distribution on a flat Si sample fabricated under the same P diffusion conditions. The precise carrier distributions in the emitter were visualized, which revealed the feature of carrier distribution in the emitter of black Si solar cell. Super-higher-order-SNDM was also employed to perform a quantitative analysis of the depletion layer distribution. It was found that the carrier density profile and the depletion layer thickness is less regular in the black Si than in the flat emitter, suggesting that this fluctuation may affect the power conversion efficiency of black Si solar cell. From above mentioned results, we confirmed that SNDM was a very useful means of investigating carrier distributions in the nano-scaled emitter of black Si solar cell.