Improved Nanophotonic Front Contact Design for High‐Performance Perovskite Single‐Junction and Perovskite/Perovskite Tandem Solar Cells

Abstract

The front contact of solar cells greatly influences the optoelectronic performance of perovskite solar cells (PSCs) by controlling the coherent light propagation as well as charge transport within the device. Herein, the nanophotonic front contact consisting of multilayer nanodomes and nanoholes for high‐efficiency perovskite single‐junction and perovskite/perovskite tandem solar cells (PVK/PVK TSCs) is investigated. The optical and electrical characteristics of solar cells are investigated by conducting an advanced 3D numerical approach with the combination of finite‐difference time‐domain (FDTD) and finite‐element method (FEM) simulations embedded with the particle swarm optimization (PSO) algorithm. The numerical modeling is validated by fabricating a set of efficient PSCs, optimized to a power conversion efficiency (PCE) of 17.9%, VOC of 1.07 V, JSC of 21.8 mA cm−2 and fill factor (FF) of 77%. The nanophotonic device results in improved JSC by 10−15%, resulting from 10−15% enhanced light incoupling compared with the planar device, while also strengthening the omnidirectional capabilities at angles of illumination as high as 40°. The optimized nanophotonic front contact results in PCEs of >23% and >30% (matched JSC ≈18 mA cm−2) for single‐junction PSCs and PVK/PVK TSCs, respectively. Details of the nanophotonic front contact, device, and fabrication process are provided.

Efficient and Stable Wide‐Bandgap Perovskite Solar Cells Derived from a Thermodynamic Phase‐Pure Intermediate

“…[20,21] Therefore, the development of wide-bandgap perovskites that can match with low-bandgap photovoltaics (such as Si, CIGS, perovskites, and so on) to prepare tandem solar cells provides a way to overcome the fundamental efficiency limits on single-junction solar cells. [22][23][24][25][26] It has been demonstrated that perovskites with a bandgap of %1.75 eV are the ideal light harvesters in perovskite/Si tandem solar cells. [27][28][29][30] So far, there are mainly two kinds of wide-bandgap perovskite candidates, all-inorganic perovskites (such as CsPbI x Br 1-x ) and organic-inorganic hybrid perovskites (such as Cs x FA 1-x Pb(I y Br 1-y ) 3 .…”

“…[ 20,21 ] Therefore, the development of wide‐bandgap perovskites that can match with low‐bandgap photovoltaics (such as Si, CIGS, perovskites, and so on) to prepare tandem solar cells provides a way to overcome the fundamental efficiency limits on single‐junction solar cells. [ 22–26 ]…”

Photonic-Structured Perovskite Solar Cells: Detailed Optoelectronic Analysis

“…Prospectively, the LT structures investigated here can also be straightforwardly applied to tandem devices (e.g., perovskite as the top cell with low-bandgap perovskite or c-Si as a sub-cell) − using adapted dimensions for maximum PV performance, while also ensuring the current matching of the sub-cells in series connection.…”

Optical Simulations in Perovskite Devices: A Critical Analysis

“…In such cases, the development of optical simulations has undoubtedly afforded great flexibility. Especially for emergent device areas such as tandem solar cells or optically pumped lasing, optical optimization can lend the last-mile performance boost that is usually unachievable through only large-scale simulations of electrical phenomena within the system. − Such computations working simultaneously enable high-throughput investigations of the optical processes that occur in a multilayer stack. For example, in device stacks that are constituted of several thin layers and interlayers, it is crucial to design the exact thickness of each layer with absolute precision to directly impact the device performance.…”