Inverted metamorphic multijunction solar cell with surface passivation

A method of manufacturing a solar cell comprising:

• providing a first substrate;
• forming an upper first solar subcell having a first band gap on said first substrate;
• forming a second solar subcell adjacent to said first solar subcell and having a second band gap smaller than said first band gap;
• forming a first graded interlayer adjacent to said second solar subcell, said first graded interlayer having a third band gap greater than said second band gap;
• forming a third solar subcell adjacent to said first graded interlayer, said third subcell having a fourth band gap smaller than said second band gap such that said third subcell is lattice mismatched with respect to said second subcell;
• forming a second graded interlayer adjacent to said third solar subcell, said second graded interlayer having a fifth band gap greater than said fourth band gap;
• forming a lower fourth solar subcell adjacent to said second graded interlayer, said lower subcell having a sixth band gap smaller than said fourth band gap such that said fourth subcell is lattice mismatched with respect to said third subcell;
• mounting a surrogate substrate on top of said fourth solar subcell;
• removing the first substrate;
• etching a first trough around the periphery of said solar cell to the surrogate substrate so as to form a mesa structure on said surrogate substrate;
• passivating an exposed surface of the solar cell with a passivating solution;
• depositing an encapsulating layer over the passivated surface by chemical vapor deposition immediately after the passivating step;
• and
• depositing an anti-reflection coating layer over the encapsulating layer.