Enhanced electron extraction capability of polymer solar cells via modifying the cathode buffer layer with inorganic quantum dots

Abstract

a Enhanced performance of polymer solar cells (PSCs) based on the blend of poly[N-9 00 -hepta-decanyl-is demonstrated by titanium dioxide (TiO 2 ) interface modification via CuInS 2 /ZnS quantum dots (CZdots). Devices with a TiO 2 /CZdots composite buffer layer exhibit both a high shortcircuit current density (J sc ) and fill factor (FF), leading to a power conversion efficiency (PCE) up to 7.01%.The charge transport recombination mechanisms are investigated by an impedance behavior model, which indicates that TiO 2 interfacial modification results in not only increasing the electron extraction but also reducing impedance. This study provides an important and beneficial approach to develop high efficiency PSCs.

Efficiency Improvement of Organic Solar Cells via Introducing Combined Anode Buffer Layer To Facilitate Hole Extraction

“…Figure a shows the J – V characteristics of the fabricated devices with various concentrations of CNDs interlayer. The control device (Device A) without any modifier indicates a J sc of 13.49 mA cm –2 , an open-circuit voltage ( V oc ) of 0.85 V, and a FF of 51.74%, leading to a PCE of 5.93%, which is at the same level of reported inverted BHJ-OSC devices fabricated under similar conditions . After CNDs were incorporated between active layer and MoO 3 , the performance of the modified devices improved remarkably.…”

“…The control device (Device A) without any modifier indicates a J sc of 13.49 mA cm −2 , an open-circuit voltage (V oc ) of 0.85 V, and a FF of 51.74%, leading to a PCE of 5.93%, which is at the same level of reported inverted BHJ-OSC devices fabricated under similar conditions. 45 After CNDs were incorporated between active layer and MoO 3 , the performance of the modified devices improved remarkably. Under an optimal modification, the PCE of Device D is 7.22% including a J sc of 14.71 mA cm −2 , a V oc of 0.86 V, and a FF of 56.93%.…”

Engineering of Porphyrin Molecules for Use as Effective Cathode Interfacial Modifiers in Organic Solar Cells of Enhanced Efficiency and Stability

“…To overcome the limitations arising from the relatively large W F , the presence of defect states and the incompatibility between the hydrophilic surface of TiO 2 and the hydrophobic polymers used in OSCs, inserting an interfacial modifier at the metal oxide/organic interface has been actively pursued. An effective approach is the use of solution-processable organic modifiers, especially polyelectrolytes with various charged groups and self-assembled monolayers, which optimize the effective W F of the metal oxide layer as well as the contact between the oxide and the photoactive film. , The decoration of the metal oxide surface with organic quantum dots has also extended its effectiveness as electron transport material in OSCs. , Compared to polymers and quantum dots, small organic molecules have numerous advantages, namely, simple modification and purification, monodispersity, and well-defined structure. Small-molecule interfacial modifiers, such as fullerene derivatives, , perylene diimides, , quinacridones, pyrene sulfonates, rhodamines, metal-phthalocyanine derivatives, , and triphenylamine–fluorene oligomers, have also been actively explored …”

“…9,10 The decoration of the metal oxide surface with organic quantum dots has also extended its effectiveness as electron transport material in OSCs. 11,12 Compared to polymers and quantum dots, small organic molecules have numerous advantages, namely, simple modification and purification, monodispersity, and well-defined structure. Small-molecule interfacial modifiers, such as fullerene derivatives, 13,14 perylene diimides, 15,16 quinacridones, 17 pyrene sulfonates, 18 rhodamines, 19 metal-phthalocyanine derivatives, 20,21 and triphenylamine−fluorene oligomers, have also been actively explored.…”

Μελέτη Μοριακών Υλικών Για Εφαρμογή Σε Οργανικές Φωτοβολταϊκές Και Φωτονικές Διατάξεις

“…Για τη βελτίωση των ενεργειακών αλλά και των επιφανειακών ιδιοτήτων του υλικού, καθώς και την ενίσχυση της αποδοτικότητας της έγχυσης και συλλογής των ηλεκτρονίων, έχει προταθεί η νόθευση του TiO2, με άτομα μετάλλων και νανοσωματίδια, όπως αυτά του αργύρου (Ag), ψευδαργύρου (Zn) και κασσιτέρου (Sn) 124 καθώς και με άζωτο (N), 125 καίσιο (Cs), 126 φθόριο αλλά και άλλα αρνητικά φορτισμένα ανιόντα. 127 Επιπλέον, η τροποποίηση του TiO2 με κβαντικές τελείες, 128 παράγωγα φουλλερενίων, 129 οξείδιο του πολυαιθυλενίου (polyethylene oxide, PEO), 130 και πολυαιθυλενιμίνη (polyethylenimine, PEI), 131 πρόσφατα αναδείχτηκε ως μια πολλά υποσχόμενη προσέγγιση για την κατασκευή διατάξεων υψηλής απόδοσης. Τέλος, οι επιφανειακές ιδιότητες του TiO2 και η απόδοση των διατάξεων μπορούν να βελτιωθούν σημαντικά με την κατάλληλη έκθεσή τους στο υπεριώδες (UV) φως, η αποκαλούμενη μέθοδος light-soaking.…”