倒装多结太阳电池的隧穿结优化

OPTIMIZATION OF TUNNEL JUNCTION IN IMM MULTI-JUNCTION SOLAR CELLS

利用MOCVD设备进行倒装多结III-V族半导体化合物太阳电池隧穿结的外延优化。利用XRD和SEM对样品进行结构分析,结果表明样品晶格质量较高,晶格匹配度良好;通过芯片工艺后,获得所需太阳电池片,I-V电学测试结果表明隧穿结带隙、厚度和掺杂是影响隧穿效应的重要因素。在隧穿结区厚度为40nm时掺杂浓度p型高达7×1019cm-3,n型高达3×1019cm-3条件下,隧穿结峰值电流能满足1000倍聚光条件下大隧穿电流的要求。在未蒸镀减反射层时,AM1.5D、1000倍聚光、25℃、low-AOD条件下,测得倒装双结太阳电池的Voc=2.776V,Isc=10.63A,FF=82.4%,Eff=24.27%。

The MOCVD epitaxial growth process of the tunnel junctions in IMM solar cells was studied. After the growth, the structural analysis as XRD and SEM show the high crystal quality of the epi-layers. I-V measurement indicates that tunnel effects strongly depend on the thickness, band gap and the doping level of the tunnel junction. When the thickness is 40nm, the carrier concentration of the p region is above 7 × 1019cm-3 and n region is above 3 ×1019cm -3, the peak current of the tunnel junction can meet the current requirement of the triple junction solar cell under the 1000 suns. Without the ARC, under 1000 suns, AM1.5D, 25℃, Low-AOD conditions, the inverted dual junction solar cell get the Voc =2. 776V, Isc = 10. 63A, FF =82. 4%, Eff=24. 27%.