Dual Bilayer for Improving Contact Quality and Passivation Enables Efficient Organic/Planar-Si Hybrid Solar Cells with a Champion V_OC of over 656 mV

Abstract

The contact quality between Si and the rear electrode and the passivation of Si play crucial roles in efficient organic/Si hybrid solar cells, especially for the open-circuit voltage (V OC ). Herein, we reported a dual bilayer structure to synergistically improve both rear contact quality and passivation of Si to enhance the performance of organic/planar-Si hybrid solar cells. Series resistance (R S ) extracted by the double diode model, contact quality explored by the Cox and Strack (CS) method, and the work function measured by ultraviolet photoelectron spectroscopy (UPS) revealed that the work function of the rear electrode effectively decreased after adding a metallic bilayer at the interface between Si and the rear electrode, which reduced the contact barrier, led to an Ohmic contact, and facilitated the transportation of electrons. Moreover, the minority carrier lifetime increased from 138.81 to 252.89 μs after applying a surfactant on top of the organic film because of the improved passivation effect. Remarkably, the best power conversion efficiency (PCE) of 14.40% for the dual bilayer planar solar cell is obtained, with a champion V OC of 656.4 mV. We provide an effective and facile strategy to design high efficiency with superior V OC by improving contact quality and passivation simultaneously in the Si-based solar cells.

Quasi‐Single Crystalline Cuprous Oxide Wafers via Stress‐Assisted Thermal Oxidation for Optoelectronic Devices

“…A τ m of 92.8 µs was fitted with a mono‐exponential decay from the decay curve of photovoltage, as shown in Figure 4b. Such a long minority carrier lifetime approaches that of crystalline silicon [ 37 ] and far surpasses that of halide perovskite single crystals. [ 38 ] Meanwhile, the BSATO method can effectively reduce defect density ( n trap ), which can be determined by the trap‐filled limit voltage using the following equation, according to the space‐charge‐limited current model [ 39 ] where ε 0 represents the vacuum permittivity, ε r the relative dielectric constant (ε r = 7.6), V TFL the onset voltage of the trap‐filled limit region, q the elementary charge (1.6 × 10 −19 C), and L (300 µm) the thickness of Cu 2 O.…”