Perovskite solar cells are amongst the most exciting photovoltaic systems as they combine low recombination losses, ease of fabrication and high spectral tunability. The Achilles heel of this technology is the device stability due to the ionic nature of the perovskite crystal, rendering it highly hygroscopic, and the extensive diffusion of ions especially at elevated temperatures. Herein, we demonstrate the application of a simple solution-processed perfluorinated self-assembled monolayer (p-SAM) that not only passivates the perovskite surface but also drastically improves the stability of the perovskite absorber and in turn the solar cell under elevated temperature or humid conditions. p-i-ntype perovskite devices employing these SAMs exhibited power conversion efficiencies surpassing 21%. Notably, the best performing devices are stable under standardized maximum-power point (MPP) operation at 85°C in inert atmosphere (ISOS-L-2) for more than 250 h, and exhibit superior humidity resilience, maintaining ~95% device performance even if stored in humid air in the ambient over months (~3000h, ISOS-D-1). Our work, therefore, demonstrates a novel strategy towards efficient and stable perovskite solar cells with easily deposited functional interlayers. Supporting Information.Experimental Methods, Supplementary Notes and Calculations, Details on Simulation, XRD, UV-Vis, XPS, FTIR, KP data, PL vs time, SPV measurements as well as additional experimental methods.

Quantitative blood cultures were obtained from 42 patients with acute Yersinia pestis infection to determine whether the concentration of bacteria in blood influenced the clinical severity and outcome of illness. In 17 bacteremic patients, colony counts in blood cultures ranged from less than 10 to 4 X 10(7)/ml. Three of five patients with colony counts of greater than 10(2)/ml died, and two patients survived episodes of hypotension. Results from plasma limulus tests were positive at the time of admission in three of 10 patients tested, and these three patients had bacteremia with colony counts of greater than 10(2)/ml. Meningitis developed in three patients and pneumonia in two patients; these five patients a-l had buboes in the axillary region. Endotoxin was detected with the limulus test in the cerebrospinal fluid in the three patients with meningitis. Ten patients randomly assigned to receive streptomycin or trimethoprim-sulfamethoxazole survived. Those treated with streptomycin had a shorter median duration of fever and a lower incidence of complications than did the patients treated with trimethoprim-sulfamethoxazole.