Enhanced Interstitial Oxygen-Enabled Efficient CuAl(M)O₂ Hole Extractors for Air-Stable All-Inorganic Perovskite Solar Cells

Abstract

The incorporation of an inorganic hole transport material (HTM) with high hole mobility and matched energetics at the back interface of perovskite/carbon plays a major role in improving the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). Here, M3+ (M = Sc, Y, and La)-doped CuAlO2, CuAl(M)O2, with superior p-type conductivity and suitable energy band is inserted between the CsPbBr3 perovskite layer and carbon electrode as an efficient HTM to enhance hole extraction and reduce energy loss within carbon-based CsPbBr3 PSCs. The balance between the increased interstitial oxygen concentration and the carrier scattering caused by the lattice distortion of CuAl(M)O2 endows a higher hole mobility of CuAl(Sc)O2, giving a substantially increased PCE of 10.13% of the CuAl(Sc)O2 tailored CsPbBr3 PSCs, compared with the 6.5% efficiency of the device without HTMs. Moreover, the CuAl(Sc)O2-based CsPbBr3 PSCs without packaging still have 90% of the original efficiency after being stored for 720 h in an air environment with a relative humidity of 85% at 85 °C, exhibiting an outstanding long-term humidity-thermal tolerance.

Porous and Ag-, Cu-, Zn-Doped Al2O3 Fabricated via Barrier Anodizing of Pure Al and Alloys

“…In each case, doped "boundary" layers can find applications. In case the exact formation of CuAlO 2 , AgAlO 2 and ZnAl 2 O 4 compounds is proved, the electrochemical synthesis of their thin layers for other promising applications actively under consideration, such as transparent conductive films [115][116][117][118][119][120][121][122][123], may be of interest for photoelectronic [124] and mechanical applications [125], optoelectronics [125], photo-thermoelectric and thermoelectric applications [126,127], fluorescence materials [128], sensors [125,[129][130][131], and electro-and photocatalysts [132][133][134][135][136].…”

Molecular engineering of methoxy-substituted terthienyl core unit based hole transport materials for perovskite solar cells

“…With more than a decade of development, the maximum certified power conversion efficiency (PCE) of perovskite solar cells (PSCs) has surged to 26.1%, and PSCs are considered as one of the most promising next-generation photovoltaic technologies. 1–6 Typically, high-performance PSC devices require the assistance of excellent hole transport materials (HTMs) with suitable energy levels, high hole mobility and conductivity to achieve efficient hole extraction and transport. 7–13 To date, 2,2′,7,7′-tetrakis ( N , N -di-pmethoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) is a state-of-art HTM that enables PSCs to achieve superior efficiency.…”

Bio-Inspired Engineering of Anti-Aging Natural Cyanidin toward Air-Stable Tin-Based Perovskite Solar Cells

“…Pb-based perovskite solar cells (PSCs) have become the shining star of photovoltaic technology and exhibited a power conversion efficiency (PCE) of 25.8% . However, from the perspective of the pursuit of pollution-free and green development in the photovoltaic field, exploration of low- or nontoxic alternatives to Pb, including bismuth (Bi), antimony (Sb), germanium (Ge), copper (Cu), tin (Sn), and other environmentally friendly cations, is important for the development of PSCs. − Sn 2+ has attracted broad attention on account of having the same electronic configuration as Pb 2+ (ns 2 np 2 ) and close ionic radii (149 and 135 pm for Sn 2+ and Pb 2+ , respectively). , Meanwhile, the band gap of Sn-based perovskite is more ideal, close to the Shockley–Queisser limit (1.3–1.4 eV), carrier mobility up to 10 2 to 10 3 cm 2 V –1 s –1 , and carrier diffusion lengths of about 10 2 to 10 5 nm. , However, the uncoordinated Sn 2+ ions on the Sn-based perovskite surface are prone to oxidation reactions with O 2 molecules, rapidly generating deep energy level defects such as Sn (IV) and Sn vacancies (V Sn ) (Sn 2+ → Sn 4+ + V Sn + 2h + → Sn 4+ + V Sn 2– + 4h + ). − Researchers have made great efforts to inhibit the valence transition of Sn 2+ . For instance, poly­(vinyl alcohol) (PVA) with hydrogen bonding was added as an additive to guide the crystal orientation .…”