Photogenerated-Carrier Collection by Induced Junction and Application to Novel Type of High-Efficiency Si Solar Cell

Abstract

A novel type of induced junction (IJ) solar cells to achieve a high efficiency without an n⁺ doped layer was proposed. A strong inversion induced by an external bias voltage across an insulating layer yields a very shallow n⁺p junction without impurity doping, and heavy doping effects can be taken away. Performances of the IJ cells were discussed in detail, and a conversion efficiency larger than 20% could be expected. A cell-fabrication process was outlined including formation of a charge-collection barrier by ion implantation and deposition of a gate insulator with a high dielectric constant. A very low sheet resistance could be realized at a low bias voltage, and the power of the photo-generated current source increased with bias voltage.