Device

In general, pre-structured indium tin oxide (ITO) substrates were cleaned with acetone and isopropyl alcohol in an ultrasonic bath for 10 min each. After drying, the substrates were coated with 40 nm of ZnO (Nanograde, N-10) by doctor-blading and then annealed at 85 ºC for 5 min Aqueous ink with 80 mg mL⁻¹ P3HT/o-IDTBR, 50 mg mL⁻¹ PCE10/o-IDTBR, PBQ-QF/o-IDTBR or PBQ-QF/ITIC particle ink was then spin-coated at 1000 rpm onto ZnO surface under ambient atmosphere. The resultant film was annealed at 150 ºC in glovebox for 10 min To complete the fabrication of the devices, 10 nm of MoO_x and 100 nm of Ag were thermally evaporated through a mask (with a 10.4 mm² active area opening, the areas were determined with the optical microscope) under a vacuum of approximately 1 × 10⁻⁶ mbar. Scan direction: forward; speed: 1 V s⁻¹; dwell time: 2 s. The current–voltage characteristics of the solar cells were measured under AM 1.5G irradiation on an OrielSollA Solar simulator (100 mW cm⁻²). The light source was calibrated by using a silicon reference cell. More than four devices (4 × 6 = 24 pixels) for each system were tested. All the devices were tested at 25 ºC in air. An Enli Technology (Taiwan) IQE measurement system (QE-R) was used for measuring EQE and reflection of solar cells. The EQE calibrated Jsc was listed in Supplementary Table ⁵. The IQE were determined following the equation: IQE = EQE/(1 – Reflection). The light intensity at each wavelength was calibrated with a standard single-crystal Si photovoltaic cell. All cells were tested under ambient air. The long-term photo-stability of P3HT:IDTBR devices were performed under continuous 1 sun illumination in a home-built chamber using a UV filter (cutoff 380 nm, the light spectrum is shown in Supplementary Fig. ²⁹) filled with N₂.