Publications de Chien-Jen Yang

Monolithic Perovskite-Silicon Tandem Solar Cells: From the Lab to Fab?

Christophe Ballif, Quentin Thomas Jeangros, Antonin Faes, Fan Fu, Chien-Jen Yang

This review focuses on monolithic 2-terminal perovskite-silicon tandem solar cells and discusses key scientific and technological challenges to address in view of an industrial implementation of this technology. The authors start by examining the different ...

Wiley-V C H Verlag Gmbh2022

Nano-emitting Heterostructures Violate Optical Reciprocity and Enable Efficient Photoluminescence in Halide-Segregated Methylammonium-Free Wide Bandgap Perovskites

Christophe Ballif, Quentin Thomas Jeangros, Peter Joseph Fiala, Christian Michael Wolff, Chien-Jen Yang, Pietro Caprioglio

This work investigates halide segregation in methylammonium-free wide bandgap perovskites by photoluminescence quantum yield (PLQY) and advanced electron microscopy techniques. Our study reveals how the formation of nano-emitting low-energy domains embedde ...

AMER CHEMICAL SOC2021

Multimodal Microscale Imaging of Textured Perovskite-Silicon Tandem Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Florent Sahli, Jérémie Werner, Alan Richard Bowman, Fan Fu, Chien-Jen Yang

Halide perovskite/crystalline silicon (c-Si) tandem solar cells promise power conversion efficiencies beyond the limits of single-junction cells. However, the local light-matter interactions of the perovskite material embedded in this pyramidal multijuncti ...

AMER CHEMICAL SOC2021

Instability of p-i-n perovskite solar cells under reverse bias

Christophe Ballif, Quentin Thomas Jeangros, Florent Sahli, Arnaud Walter, Daniel Anthony Jacobs, Fan Fu, Ricardo Augusto Zanotto Razera, Sylvain Nicolay, Peter Joseph Fiala, Laura Ding

Partial shading can trigger permanent damage in photovoltaic modules because the illuminated solar cells drive the shaded cells into reverse bias. Under reverse bias conditions, perovskite solar cells have been shown to degrade quickly due to processes tha ...

Royal Society of Chemistry2020

How far does the defect tolerance of lead-halide perovskites range? The example of Bi impurities introducing efficient recombination centers

Wolfgang Richard Tress, Simone Meloni, Zaiwei Wang, Björn Niesen, Juan-Pablo Correa-Baena, Chien-Jen Yang, Mozhgan Yavari, Firouzeh Ebadi Garjan

One of the key properties of lead-halide perovskites employed in solar cells is the defect tolerance of the materials, in particular regarding intrinsic point defects, which mainly form shallow traps. Considering that high luminescence yields and photovolt ...

Royal Society of Chemistry2019

Multiple Charge Transfer States in Donor-Acceptor Heterojunctions with Large Frontier Orbital Energy Offsets

Xiao Liu, Björn Niesen, Chien-Jen Yang

In this work, we demonstrate several organic amorphous donor-acceptor systems that exhibit sub-bandgap features over a more than 2 eV spectral range. An in-depth study of one of these systems, NPB:HAT-CN (NPB is N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biph ...

2019

High-temperature annealing effects on molybdenum-silicon contact substrate for vertically structured silicon quantum-dot solar cells

Chien-Jen Yang

This paper studies the applicability of sputtered Molybdenum (Mo) thin films on silicon wafers (Mo-Si) to act as contact substrates for vertically structured Si quantum-dot (QD) solar cells. The compatibility of Mo-Si contact substrate with Si QD material ...

2019

Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV

Christophe Ballif, Jérémie Werner, Quentin Thomas Jeangros, Matthias Wolfgang Bräuninger, Gabriel Christmann, Florent Sahli, Arnaud Walter, Sylvain Nicolay, Björn Niesen, Gizem Nogay

Cesium-formamidinium-based mixed-halide perovskite materials with optical band gaps ranging from 1.5 to 1.8 eV are investigated by variable-angle spectroscopic ellipsometry. The determined complex refractive indices are shown to depend on the fabrication p ...

2018

Post-Sputtering Heat Treatments of Molybdenum on Silicon Wafer

Chien-Jen Yang

This paper investigated the property evolutions of Mo thin films that were subjected to post-sputtering heat treatments from 700 degrees C to 1100 degrees C. It was found that, after annealing, the use of Si wafers eliminated crack formations found in prev ...

2018

Hybrid sequential deposition process for fully textured perovskite/silicon tandem solar cells

Christophe Ballif, Quentin Thomas Jeangros, Davide Sacchetto, Bertrand Yves Paul Paviet-Salomon, Florent Sahli, Arnaud Walter, Gianluca Cattaneo, Matthieu Despeisse, Mathieu Gérard Boccard, Sylvain Nicolay

Tandem solar cells that feature a high-bandgap perovskite cell on top of a lower bandgap silicon cell have the potential to reach efficiencies > 30%. Here, we present a versatile hybrid deposition method that yields conformal perovskite cells directly on t ...

IEEE2018