Surface arrays of subwavelength photoactive structures have been demonstrated for photovoltaic (PV) applications with elevated omnidirectional and broadband absorption. However, this approach suffers from an increase in surface recombination and loss of photovoltage. Herein, surface decoration with subwavelength dielectric (SiO₂) arrays that provide enhanced light trapping without compromising the photovoltage performance is proposed. An increase of ≈ 50% in broadband absorption is shown in an ultrathin film of 200 nm due to the presence of a top surface SiO₂ nanopillar array in comparison with the same film decorated with an optimized antireflective coating of 50 nm of Si₃N₄. Interestingly, the broadband enhancement is not due to lower reflection, but rather the presence of the arrays forces a considerable lower transmission. The distribution of the optical power flux density suggests that the low transmission is due to appreciable refraction, which is induced by the presence of the dielectric arrays. Finally, the photovoltaic performance is examined for various array geometries and absorber acceptor concentrations and an overall increase of >60% in PV efficiency is calculated for a decorated photovoltaic cell in comparison with a PV cell with an antireflection coating of 50 nm Si₃N₄.

中文翻译：

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克服基于亚波长阵列的薄膜光伏电池高表面复合的挑战，用于提升光捕获

亚波长光敏结构的表面阵列已被证明用于具有高全向和宽带吸收的光伏 (PV) 应用。然而，这种方法会增加表面复合和光电压损失。在此，提出了具有亚波长电介质 (SiO ₂ ) 阵列的表面装饰，可在不影响光电压性能的情况下提供增强的光捕获。与用 50 nm Si ₃ N ₄优化抗反射涂层装饰的同一薄膜相比，由于顶面 SiO ₂纳米柱阵列的存在，200 nm 超薄膜的宽带吸收增加了 ≈ 50%. 有趣的是，宽带增强不是由于较低的反射，而是阵列的存在迫使传输相当低。光功率通量密度的分布表明低传输是由于明显的折射，这是由介电阵列的存在引起的。最后，检查了各种阵列几何形状和吸收体受体浓度的光伏性能，与具有 50 nm Si ₃ N ₄抗反射涂层的 PV 电池相比，装饰光伏电池的 PV 效率总体增加了 >60% .