High efficiency organic/a-Si hybrid tandem solar cells with complementary light absorption

Abstract

Organic/amorphous silicon (a-Si) hybrid tandem solar cells have the potential to provide a highly efficient low-cost photovoltaic technology using abundant elements, and the technology is adaptable to large-scale processes. With their high open-circuit voltage (V oc ) and adaptability to a broad solar spectrum, organic/a-Si tandem devices offer significantly improved performance. We have shown that organic/a-Si hybrid tandem solar cells with a complementary organic absorber can exhibit a power conversion efficiency (PCE) of up to 7.5%, with a fill factor (FF) of 72.3% and a V oc almost equivalent to the sum of the sub-cells under standard air mass (AM) 1.5 illumination. The high performance of the device results from the complementary absorption spectra of two sub-cells and well-matched energy levels of the intermediate layer. This study provides an effective design strategy for organic/a-Si hybrid tandem solar cells of improved efficiency.

Highly Efficient Hybrid Polymer and Amorphous Silicon Multijunction Solar Cells with Effective Optical Management

“…Electrically, an efficient ICL should form an ohmic recombination contact between the subcells and have a suitable work‐function difference to sum up the V oc of the individual subcells. Previous studies have shown that AZO/Ag/MoO 3 , AZO/pH‐neutral poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (n‐PEDOT:PSS), and ITO/PEDOT:PSS are efficient ICLs to electrically connect the a‐Si:H and polymer constituent subcells . However, the role of the optical properties of the ICL in the hybrid multijunction solar cells has not yet been well recognized and studied.…”

Photovoltaic device based on TiO2 rutile/anatase phase junctions fabricated in coaxial nanorod arrays

“…Semiconductor heterojunction plays an important role in photogenerated charge separation of photocatalytic [1][2][3] and photovoltaic [4,5] systems for solar energy conversion. A heterojunction, usually formed between two different semiconductors [6][7][8] or semiconductors with different doping levels [9,10], provides the potential driving force for separating photoinduced charge carriers at the interface.…”

Hybrid Organic/Inorganic Thin‐Film Multijunction Solar Cells Exceeding 11% Power Conversion Efficiency

“…This leads to the need of depositing a rather thick μc‐Si:H layer (typically >1 μm at low deposition rates of about 0.5 nm s −1 ) and the incorporation of light trapping architectures in order to efficiently absorb low‐energy photons. These considerations have drawn the attention to fabricate thin‐film hybrid multijunction architectures comprising a high bandgap a‐Si:H front subcell and a low bandgap organic back subcell . While the PCEs for such double junction (DJ) devices was initially quite low (≈1.8%), they have quadrupled over the last three years, now reaching more than 7.5% PCE .…”

“…These considerations have drawn the attention to fabricate thin‐film hybrid multijunction architectures comprising a high bandgap a‐Si:H front subcell and a low bandgap organic back subcell . While the PCEs for such double junction (DJ) devices was initially quite low (≈1.8%), they have quadrupled over the last three years, now reaching more than 7.5% PCE . This progress was mainly achieved due to new, low bandgap donor polymers, and a thorough tuning of the subcell contacts to establish an efficient series connection between the front and the back cell.…”