Optoelectronic devices utilizing multiple quantum well pin structures

An optoelectronic device comprising:

• a substrate comprised of semiconductor material;
• a first substantially transparent, electrically conductive layer of a first conductivity type having an upper surface and a lower surface and disposed on said substrate, said first conductive layer being doped to a first conductivity type to obtain a surface impurity concentration of between approximately 6.times.10.sup.13 to 6.times.10.sup.14 atoms/cm.sup.2 ;
• a quantum-well intrinsic region formed on said first conducting layer, said quantum-well intrinsic region comprising a buffer layer grown on said first conductive layer, said buffer layer having an upper surface and a lower surface and being doped with a dopant for forming a doping gradient having maximum impurity concentration at said lower surface of at least 1.times.10.sup.18 atoms/cm.sup.3 and a minimum surface impurity concentration at said upper surface of at least 1.times.10.sup.15 atoms/cm.sup.3 ;
• and
• a second substantially transparent, electrically conductive layer formed on said quantum-well intrinsic region and doped to a second conductivity type.