Spectral Splitting Solar Cells Constructed with InGaP/GaAs Two-Junction Subcells and Infrared PbS Quantum Dot/ZnO Nanowire Subcells

Abstract

We constructed an infrared PbS colloidal quantum dot (QD)/ ZnO nanowire (NW) solar cell to develop a solution-processed bottom solar cell for multijunction solar cells. PbS QD/ZnO NW interdigitated structures comprising 1 μm long ZnO NWs enable the construction of spatially separated carrier pathways and thick PbS QD layers for high infrared light harvesting. Additionally, optical management plays an essential role in the harvesting process. Using infrared transparent conductive oxides as window layers and a wide-band-gap QD electron blocking layer (EBL), the parasitic absorption of the EBL is reduced and the reabsorption of the light reflected is enhanced by the metal back contact. Thus, the developed solar cell produced a short-circuit current density of 39.2 mA/cm 2 under 1 sun illumination and 17.4 mA/cm 2 over an 870 nm infrared region. Furthermore, series-connected spectral splitting solar cells, comprising an InGaP/GaAs top/ middle (2J-TM) subcell and the infrared PbS CQD/ZnO NW bottom (1J-B) subcell, yielded a power conversion efficiency of 30.5% under 1 sun illumination.

Colloidal quantum dot materials for next-generation near-infrared optoelectronics

“…2g). 48 Using a dichroic mirror, NIR with wavelengths over 870 nm is transmitted onto the PbS CQD subcell (bottom of the mirror) and other wavelengths onto the InGaP/ GaAs subcell (side of the mirror). The PbS CQD subcells were designed in a ZnO/PbS-TBAI/PbS-EDT architecture, and the main absorbing layer, PbS-TBAI, is with the first-excitonic peak at 1550 nm.…”

Quantum Junction Solar Cells: Development and Prospects

“…Panels (a) to (d) were adapted with permission. [ 53 ] Copyright 2022, American Chemical Society. e) The MOETL‐free QJ structure that was used in our research is shown schematically and in cross‐sectional SEM images.…”

“…n) The target device is shown in a schematic diagram. [ 53 ] Copyright 2021, American Chemical Society. o) Planar heterojunction structure for the SnO 2 ‐based PSCs is shown schematically.…”

“…d)The ideal solar cell's EQE (blue) and IQE (dotted black) spectra, also displayed is the cumulative photocurrent density (red) derived from the EQE spectrum. Panels (a) to (d) were adapted with permission [53]. Copyright 2022, American Chemical Society.…”

Organic Solar Cells: Physical Principle and Recent Advances

“…It is known that conventional inorganic solar cells are developed early and widely used, accounting for more than half of the market share. The high power conversion efficiency (PCE) of conventional inorganic solar cells is the primary attribution, such as >29 % of silicon [6] and >30 % of GaAs [7] . However, inorganic solar cells have many defects since their inception, making them challenge for mass production.…”