Fully Inkjet-Printed Green-Emitting PEDOT:PSS/NiO/Colloidal CsPbBr3/SnO2 Perovskite Light-Emitting Diode on Rigid and Flexible Substrates

After establishing themselves as promising active materials in the field of solar cells, halide perovskites are currently being explored for fabrication of low-cost, easily processable, and highly efficient light-emitting diodes (LEDs). Despite this, the highest efficiencies reported for perovskite-based LEDs (PeLEDs) are achieved through spin coating or vacuum evaporation deposition techniques, which are not adequate, in most of the cases, for an industrial-scale production. Additionally, the long-term stability is still a big handicap, even though all inorganic perovskites, such as CsPbBr3, are found to be more stable to external variables. In this context, herein, the fabrication of fully inkjet-printed (IJP) CsPbBr3-based PeLEDs in ambient conditions, on rigid and flexible substrates, on a proof-of-concept basis, with the successful incorporation of NiO and SnO2 as hole- and electron-selective contacts, respectively, is reported. Despite the moderate luminance (324 cd m−2) value obtained, this result paves the way toward the development of upscalable fabrication of PeLEDs based on deposition techniques with controlled spatial resolution.The authors wish to thank the financial support from the European Commission via FET Open Grant (862656, DROP-IT), MINECO (Spain) for grant PID2019-105658RB-I00 (PRITES project), Ministry of Science and Innovation of Spain under Project STABLE (PID2019-107314RB-I00), and Generalitat Valenciana via Prometeo Grant Q-Devices (Prometeo/2018/098)

Preparing company to energy audit

The main objective of energy audit is to present any irregularities in work of energy facilities and show possibilities of increasing energy efficiency. There is possibility to perform different types of energy audits: basic energy audit (presents basic and cheap improvements), full energy audit (contains a lot of measurements and full economical analysis) or individual energy audit (analyzes selected part of the production process or energy installation). First part of article contains question, which management should discuss before decision on preparing energy audits. This issues helps choose type of report and processes to analyze. Additionally management can plan the amount of financed expenses related to energy modernization and connected profits. There is possibility to delegate person from company to prepare an energy audit. Is this a reasonable decision? Auditor has an experience and has worked with a lot of different energy problems. This means that proposed solutions will be more vary and economic analyzes will include more aspects. Furthermore auditor will evaluate objective with comparison to employees. Auditor needs a lot of data to prepare reliable report. Therefore cooperation between company staff and auditors should proceed properly. Article contains examples of questions, which can be included in the questionnaire, and steps of updating documents. Finished report is discussed on a final meeting, where management decides which improvement will be implementing. After modification it is recommended to prepare another energy audit