Perovskite/SHJ tandem solar cells

With single-junction solar cells approaching the Shockley-Queisser limited conversion efficiency, integrating the wide bandgap top perovskite solar cells with crystalline bottom solar cells to form tandem solar cells is considered as a promising strategy for a better utilization of the solar spectrum, in order to further increase solar cell efficiency. In IEK-5, we aim at bringing our advantages in high efficiency silicon heterojunction (SHJ) solar cell and perovskite solar cell development together, to develop a perovskite/SHJ tandem technology with efficiency above 30%.

Research Topics:

1. Optimization of the SHJ bottom cell
• High efficiency SHJ solar cells based on different wafer strategy, such as single-side textured wafer, two-side nano-sized textured wafer
• Soft deposition of transparent conductive layer
2. Optimization of perovskite top cell
• Soft deposition of transparent electrodes
• Exploration of suitable hole transport layers (metal oxides, polymers, small molecules and self-assembled monolayers)
• Bandgap tuning by varying perovskite composition
• Electron transport layer process development via Atomic Layer Deposition (ALD) and/or spin coating techniques
3. Optimization of tandem device
• Process development of perovskite deposition on different SHJ bottom cells
• Current matching between top and bottom cells
• Optimization of intermediate recombination layer
4. Optimization of opto-electrical design for tandem by advanced device simulation
• Design of front and interlayers with micro-/nano-optical approaches
• Reduction of power losses at the interlayers by improved engineering of the layer stack