Temperature, and laser fluence swept millimeter wave response datasets for a 48,000 hour old encapsulated methyl ammonium lead iodide thin film

Published: 2 May 2023| Version 1 | DOI: 10.17632/tpg5g269cj.1
Biswadev Roy


Metal halide perovskites are very strong candidates for use in photovoltaic conversion, as photodetectors, in optically pumped lasers and now in field effect transistors. We have subjected the very old thin film sample of Methylammonium lead Iodide (MAPbI3) with quartz substrate (glass encapsulated) to sweeping laser intensity and temperature (300K – 7K) simultaneously. Room temperature datasets of this old sample were already published in Mendeley Data, V4, doi: 10.17632/p65yxhdxkm.4 with all sample preparation and other details. These new data pertain to the IMPATT produced probe frequency of 120 GHz while 1 kHz pulsed laser beam at 532nm on the sample inside an ARS cryocooler model number DE-202/AI with Lakeshore 330 controller. The art of data collection remained the same however, the laser maximum fluence changed substantially in these sets of experiments due to passing the laser through the optical elements in the path and fitted on to the cryostat. The millimeter wave response ratio represents the lumped product of carrier-mobility and carrier concentrations for the given temperature and laser fluence levels. Carrier density changes with laser intensity nonlinearly, and the free carrier charge mobility changes with temperature and electric field of the probe beam. In our time-resolved TR-mmWC apparatus, the glass-covered sample was excited by a 1KHz triggered 532 nm laser beam with a width of 0.7 ns with maximum fluence 5.2 microjoules per sq. cm and a spot size around 10mm. Transient datasets were recorded using a 6 GHz input bandwidth digitizer after amplifying Schottky detector registered radiofrequency (RF) signal due to differential absorption of the passing millimeter wave from source (normal to sample) at 120 GHz through sample. Signal averaging was done 10,000 times and data of the same sample were collected on 2 different dates November 21, and November 23, 2023, respectively. The data attached are CSV files with column 1 being the pump-probe delay time (second), and column 2 being voltage response (V). Examples: File with name “November-23-2022-NCSU-Perovskite-Cryostat-200-8K-FullLaserPwr-120GHz.csv” means the date is Nov. 23, Temperature is 200.8K (un-calibrated) should read 7K (calibrated, DC 28.4 mV), Full Laser Power representing 5.2 microjoules/cm2 laser fluence, 250.8K should be read as 55K(DCV 28.4 mV), 350.8K as 151K (DCV 28.9 mV) and 443.8K as 241K (DCV 33.6 mV). For November 21, 2023, the temperature was swept more frequently. The filenames also carry the uncalibrated temperatures that the calibrated temperatures (K) should be read as 6.262 6.262 6.262 11.079 25.529 35.163 44.797 54.431 73.699 83.333 102.601 117.052 160.404 170.038 179.672 194.123 198.940 218.208 227.842 244.219 272.158 272.158 272.158 272.158 272.158 272.158 respectively. The DCV appears in the November 21 filenames themselves.


Steps to reproduce

A 300nm thin film of methylammonium lead iodide has to be deposited on sapphire substrate and covered with glass, with no leakage. The sample has to be placed inside a cryocooler with two windows (front and back) for passing the laser beam for excitation and passing the probe meab to receive the differential absoprtion signals received using a horn antenna fed Schottky detector. The received signal (based on the pulsed laser on/off state) has to be low noise amplified and averaged 10,000 times before saving the signal as a .csv file for analysis. The DC voltages are collected from the DC port of the Schottky diode bias tee and averaged using a multimeter or a digital multimeter.


North Carolina Central University


Materials Science


National Science Foundation

HRD 2200518