High-voltage metamorphic 1064 nm InGaAs multi-junction laser power converters

Metamorphic InGaAs laser power converters (LPCs) grown on GaAs are ideal candidates for long-distance high-power electrical energy transmission. In this work, metamorphic 1064 nm In0.25Ga0.75As six-junction LPCs have been grown on a misoriented (100) GaAs substrate by employing a compositionally graded AlGaInAs metamorphic buffer with reverse and overshoot layers to accommodate the 1.8% mismatch. The metamorphic LPC wafers are processed into LPCs with an aperture of 3 × 3 mm2 and characterized, exhibiting a maximum conversion efficiency of 28.26% with an open-circuit voltage of 4.59 V, and a fill factor of 81.76% at an incident laser power density of 14.05 W/cm2. The open-circuit voltage and conversion efficiency show a temperature coefficient of −8.46 mV/K and −0.063%abs/K, respectively. The experimental results demonstrate the feasibility of multi-junction metamorphic 1064 nm LPCs on GaAs substrates.