Embedded junction in hetero-structured back-surface field for photovoltaic devices

摘要

A photovoltaic device and method include a crystalline substrate and an emitter contact portion formed in contact with the substrate. A back-surface-field junction includes a homogeneous junction layer formed in contact with the crystalline substrate and having a same conductivity type and a higher active doping density than that of the substrate. The homogeneous junction layer includes a thickness less than a diffusion length of minority carriers in the homogeneous junction layer. A passivation layer is formed in contact with the homogeneous junction layer opposite the substrate, which is either undoped or has the same conductivity type as that of the substrate.

主权项

1. A photovoltaic device, comprising:
a crystalline substrate; an emitter contact portion formed in contact with the substrate; and a back-surface-field junction including: a homogeneous junction layer in contact with the crystalline substrate having a same conductivity type and a higher active doping density than that of the substrate, wherein the homogeneous junction layer includes a thickness less than a diffusion length of minority carriers in the homogeneous junction layer, wherein the thickness of the homogeneous junction layer ranges from 1 nm to 100 nm, and the diffusion length of the minority carriers ranges from 50 nm to 2 microns; wherein the homogeneous junction layer includes hydrogenated single-crystalline material; and a passivation layer formed in contact with the homogeneous junction layer opposite the substrate, which is either doped or undoped.