Lead (II) Iodide (99.99%, trace metals basis), SAM (([2-(9H-carbazol-9-yl)ethyl]phosphonic acid), 2PACz) were purchased from Tokyo Chemical Industry (TCI). Methylammonium iodide (MAI), was purchased from Dynamo. Bathocuproine (BCP) was purchased from Ossila. Ethanol (anhydrous) was purchased from VWR Chemicals and Copper Shots was purchased from Alfa Aesar. Other chemicals were purchased from Sigma-Aldrich. All the chemicals were used as received without purification.
MHP semiconductors inks preparation
MAI and PbI2 were mixed in a vial and dissolved with 2-methoxyethanol (2-ME) as a 2-ME ink (1M) and stirring overnight at room temperature. DMSO (around 11.77 mol%, 23.56 mol%, 35.33 mol%, 47.10 mol%, 58.88 mol% DMSO) was put into 2-ME ink before coating.
SAM powders were dissolved in anhydrous Ethanol at a concentration of 0.5mg/ml and put into an ultrasonic bath for 15 min (~ 45 °C) before using24.
Slot die coating MHP semiconductors and devices fabrication.
The configuration of P-I-N devices
ITO (150nm)/SAM (2PACz)/MAPbI3 (~800 nm)/C60 (23 nm)/BCP (8 nm)/Cu (100 nm)
The cleaning procedure of patterned Indium tin oxide (ITO, 15 Ω sq-1, 150 nm) are the same with before26. In brief, ITO glasses were cleaned by Mucasol solution in deionized water (DI water), DI water, acetone and isopropanol at around 40 °C for 15 minutes each.
Before spin-coating SAM, the ITO glasses were pre-clean with 15 minutes UV-ozone treatment. Then SAM layer was spin coated at the speed of 3,000 r.p.m for 30 s, (ramping: 1,000/s) and then annealed at 100 °C for 10 min.
SDC MHP semiconductors and devices making
The slot die coater (FOM technologies) which is composed of an ink reservoir, pump systems, slot-die head, and a temperature-controlled bottom plate (vacuum chuck) mounted on a conveyor belt system. An air knife for N2 gas quenching can be optionally mounted in the system. In brief, when coating begins, the pump systems precisely control how much ink (pump rate) flows through a tube into the slot die head to substrates, and the conveyor system determines the coating speed and direction.
MHP semiconductors inks were pipetted into a syringe connecting to a tube, which is controlled by pump (pump rate fix how much ink is pouring down out of the tube into die head per second). Coating speed is 20 cm/min, pump rate is 50 µl/min, gap is around 0.2-0.3 mm, air knife pressure is approximately 20 psi at room temperature. The MHP semiconductors were annealed at 100 °C for 20 minutes.
After cooling down to room temperature, the substrates were transferred to the evaporation system (MBRAUN ProVap 3G). The BCP (8 nm), C60 (23 nm) and copper (100 nm) layers were subsequently deposition by thermal evaporate method. The evaporate rate of BCP is 0.1 Å/s, C60 is 0.05 Å/s to 0.1 Å/s, and the rate of copper is 0.1 Å/s to 1 Å/s at base pressure of 1 × 10-6 mbar. For the champion devices, a 100 nm NaF (Sodium Fluoride) layer was deposited upon the glass side at base pressure of 1 × 10-6 mbar, with rate of 0.1 - 1 Å/s
A LabView programmed Keithley 2400 SMU was used to record current–voltage (J–V) measurements parameters under AM 1.5G 100 mW/cm2 (Oriel LCS-100 class ABB solar simulator) in a N2-filled glovebox, calibrated with silicon reference cell (Fraunhofer ISE). The active area of all devices reported in this work is 0.16 cm2 defined by the overlap area of patterned ITO and masked copper electrode. A 0.09 cm2 mask determined by microscope imaging was used to define the active area precisely. The measurement was carried on at room temperature in a N2-filled glovebox without any preconditioning. The scan directions are 1.2 V to −0.02 V (reverse) or −0.02 V to 1.2 V (forward), with 20ms delay time, 40ms integration time and 20mV voltage step. In the TrAMPPT measurement, the J-V curves of corresponding devices were measured just after the TrAMPPT test, with integration time of 0.2 ms, 0.2 ms, 1 ms, 10 ms, 20 ms, 30 ms and settling time of 0.1 ms, 1ms, 10ms, 100ms, 1,000ms, 3,000ms.
The external quantum efficiency (EQE) measuremnts (from 300 to 850 nm) were performed using Oriel Instruments QEPVSI-b system with a Xenon arc lamp (Newport 300 W, 66902) chopped at 35.5 Hz and a monochromatic instrument (Newport Cornerstone 260)26.
The scanning electron measurements (SEM) images (top view and cross-section) were measured by Hitachi S-4100 at 5 kV.
In-situ grazing incidence wide-angle X-ray scattering (GIWAXS) measurements were conducted at KMC-2 beamline21 at the synchrotron source BESSY II (Helmholtz-Zentrum Berlin). The photon energy of the source is 8048 eV. Incident angle was fixed at 2 deg. We use the area detector Bruker AXS. The detector was kept on 9 degrees to collect the scattering. An Anton Paar setup was used to control the substrate temperature and the temperature ramp is around 45 °C/min During measurement, the samples were kept under constant nitrogen gas flow (6 liter/hour) connected to the Anton Paar setup.