ScholarWorks@성균관대학교

초록

This study reports a current-matched two-terminal (2T) tandem solar cell comprising a GaInP/GaAs/InGaAs triple-junction III-V top cell with a fully back-metalized commercial device efficiency of 29.96%. This top cell is integrated with an n-type tunnel oxide passivated contact (n-TOPCon) silicon bottom cell, which delivers an efficiency of 22.03%. To mitigate the photon transmission barrier imposed by the fully back-metalized III-V structure, we first optimize the silicon bottom cell area, achieving an efficiency of 27.41% with current matching at 14.4 cm2. A further enhancement is realized by introducing rear-side albedo illumination (0.3 sun) while maintaining equal top and bottom cell areas as 12.04 cm2, resulting in a significantly improved tandem efficiency of 35.33% with J sc = 13.03 mA cm-2, V oc = 3.58 V, and FF = 75.70%. These experimentally obtained electrical parameters for the Si, III-V, and III-V/Si tandem devices were individually used as inputs in PVsyst simulation software for a 1 MW photovoltaic system. The tandem configuration delivers an annual energy output of 1222.1 MWh to the grid with a performance ratio (PR) of 0.920, surpassing standalone Si and III-V modules. System-level loss analysis showed Si modules exhibited higher thermal and LID losses, while III-V suffered greater voltage degradation from temperature effects. Furthermore, the tandem configuration exhibited reduced spectral, thermal, mismatch, and wiring losses with stable inverter output demonstrating a practical strategy for high-efficiency tandem photovoltaics.

키워드