Quantitative measurement of active dopant density distribution in phosphorus-implanted monocrystalline silicon solar cell using scanning nonlinear dielectric microscopy

The performance of silicon (Si) solar cells is dependent on the active dopant distribution in emitters. Estimation of the dopant distribution in a Si solar cell fabricated by ion implantation is difficult due to the pyramidal surface texture of the emitter. Here, we investigate the active dopant distribution in a P-implanted Si solar cell using scanning nonlinear dielectric microscopy (SNDM). SNDM and dC/dz-SNDM are complementarily applied to visualize the carrier distribution in the cross section of the Si solar cell. The carrier density in the emitter is calibrated using the SNDM data obtained from Si standard samples. The results show that the dopant distribution can be described as the sum of two Gaussian functions distributed over the vertical direction of the pyramidal faces. The three-dimensional (3D) dopant distribution is estimated from the superposition of the P distributions at each pyramidal face. The estimated 3D dopant distribution is in good agreement with the SNDM measurement results.