A GalnP/AlGaAs broadband tunnel junction （TJ） with a peak current density of 65.3 A/cm2 and an AlGalnP/AlGaAs ultrabroad band TJ with a peak current density of 6.1 A/cm2 were studied and fabricated. Di- ethyltelluri...A GalnP/AlGaAs broadband tunnel junction （TJ） with a peak current density of 65.3 A/cm2 and an AlGalnP/AlGaAs ultrabroad band TJ with a peak current density of 6.1 A/cm2 were studied and fabricated. Di- ethyltellurium （DETe） was chosen as an n-type dopant in the TJ. The growth temperature, valve switching and flow variation parameters of DETe were studied for better performance. Measurements, including predoping of DETe before growth and heating up reactor temperature after growth, were taken to deal with the effect of turn-on and off of tellurium. The strain balance method was used to the manage lattice mismatch that was introduced by the tellurium. Various flows of DETe were studied to get the appropriate value needed to fabricate a high peak current density tunnel junction.展开更多
Direct wafer bonding technology is able to integrate two smooth wafers and thus can be used in fab- ricating III-V multijunction solar cells with lattice mismatch. In order to monolithically interconnect between the G...Direct wafer bonding technology is able to integrate two smooth wafers and thus can be used in fab- ricating III-V multijunction solar cells with lattice mismatch. In order to monolithically interconnect between the GalnP/GaAs and InGaAsP/InGaAs subcells, the bonded GaAs/InP heterojunction must be a highly conductive ohmic junction or a tunnel junction. Three types of bonding interfaces were designed by tuning the conduction type and doping elements of GaAs and InP. The electrical properties of p-GaAs （Zn doped）/n-InP （Si doped）, p- GaAs （C doped）/n-InP （Si doped） and n-GaAs （Si doped）/n-InP （Si doped） bonded heterojunctions were analyzed from the I-V characteristics. The wafer bonding process was investigated by improving the quality of the sample surface and optimizing the bonding parameters such as bonding temperature, bonding pressure, bonding time and so on. Finally, GalnP/GaAs/InGaAsP/lnGaAs 4-junction solar cells have been prepared by a direct wafer bonding technique with the high efficiency of 34.14% at the AM0 condition （1 Sun）.展开更多
文摘A GalnP/AlGaAs broadband tunnel junction （TJ） with a peak current density of 65.3 A/cm2 and an AlGalnP/AlGaAs ultrabroad band TJ with a peak current density of 6.1 A/cm2 were studied and fabricated. Di- ethyltellurium （DETe） was chosen as an n-type dopant in the TJ. The growth temperature, valve switching and flow variation parameters of DETe were studied for better performance. Measurements, including predoping of DETe before growth and heating up reactor temperature after growth, were taken to deal with the effect of turn-on and off of tellurium. The strain balance method was used to the manage lattice mismatch that was introduced by the tellurium. Various flows of DETe were studied to get the appropriate value needed to fabricate a high peak current density tunnel junction.
基金Project supported by the Shanghai Rising-Star Program(No.14QB1402800)
文摘Direct wafer bonding technology is able to integrate two smooth wafers and thus can be used in fab- ricating III-V multijunction solar cells with lattice mismatch. In order to monolithically interconnect between the GalnP/GaAs and InGaAsP/InGaAs subcells, the bonded GaAs/InP heterojunction must be a highly conductive ohmic junction or a tunnel junction. Three types of bonding interfaces were designed by tuning the conduction type and doping elements of GaAs and InP. The electrical properties of p-GaAs （Zn doped）/n-InP （Si doped）, p- GaAs （C doped）/n-InP （Si doped） and n-GaAs （Si doped）/n-InP （Si doped） bonded heterojunctions were analyzed from the I-V characteristics. The wafer bonding process was investigated by improving the quality of the sample surface and optimizing the bonding parameters such as bonding temperature, bonding pressure, bonding time and so on. Finally, GalnP/GaAs/InGaAsP/lnGaAs 4-junction solar cells have been prepared by a direct wafer bonding technique with the high efficiency of 34.14% at the AM0 condition （1 Sun）.
