Thinned GaInP/GaInAs/Ge solar cells grown with reduced cracking on Ge|Si virtual substrates

Reducing the formation of cracks during growth GaInP/GaInAs/Ge 3-junction solar cells on Ge|Si virtual substrates has been attempted by thinning structure, namely Ge bottom cell and GaInAs middle cell. The theoretical analysis performed using realistic device parameters indicates that can be drastically thinned to 1000 nm while increasing its In content 8% with an efficiency loss in below 3%. experimental results show macroscopic is prevented GaInAs/Ge 2-junction cells. These prototype crack-free multijunction demonstrate concept were used rule out any possible component integration issue. performance metrics are limited high threading dislocation density over 2e7cm-2 used, but almost current matched, crack-free, demonstrated, pathway towards higher voltages identified.