Solar cell structures for improved current generation and collection

An optoelectronic device comprising a photovoltaic cell, the photovoltaic cell comprising:

• a space-charge region;
• a quasi-neutral region;
• and
• a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer forming a first portion of a base layer of the cell;
• a window layer;
• a back-surface-field (BSF) layer;
• an emitter layer;
• a second portion of the base layer;
• and
• a third portion of the base layer
• wherein the first portion of the base layer is disposed between the second portion of the base layer and the third portion of the base layer, the second portion of the base layer being adjacent the emitter layer, the third portion of the base layer being disposed between the first portion of the base layer and the BSF layer.