Dopant-Tunable Ultrathin Transparent Conductive Oxides for Efficient Energy Conversion Devices

Ultrathin film-based transparent conductive oxides(TCOs)with a broad work function(WF)tunability are highly demanded for e cient energy conversion devices.However,reducing the film thickness below 50 nm is limited due to rapidly increasing resistance;furthermore,introducing dopants into TCOs such as indium tin oxide(ITO)to reduce the resistance decreases the transparency due to a trade-o between the two quantities.Herein,we demonstrate dopant-tunable ultrathin(≤50 nm)TCOs fabricated via electric field-driven metal implantation(m-TCOs;m=Ni,Ag,and Cu)without com-promising their innate electrical and optical properties.The m-TCOs exhibit a broad WF variation(0.97 eV),high transmittance in the UV to visible range(89–93%at 365 nm),and low sheet resistance(30–60Ωcm-2).Experimental and theoretical analyses show that interstitial metal atoms mainly a ect the change in the WF without substantial losses in optical transparency.The m-ITOs are employed as anode or cathode electrodes for organic light-emitting diodes(LEDs),inorganic UV LEDs,and organic photovoltaics for their universal use,leading to outstanding performances,even without hole injection layer for OLED through the WF-tailored Ni-ITO.These results verify the proposed m-TCOs enable e ective carrier transport and light extraction beyond the limits of traditional TCOs.

Organic photodiode with dual functions of indoor photovoltaic and high-speed photodetector

Energy harvesting and light detection are key technologies in various emerging optoelectronic applications.The high absorption capability and bandgap tunability of organic semiconductors make them promising candidates for such applications.Herein,a poly(3-hexylthiophene-2,5-diyl)(P3HT):indene-C60 bisadduct(ICBA)bulk heterojunction-based organic photodiode(OPD)was reported,demonstrating dual functionality as an indoor photovoltaic(PV)and as a high-speed photodetector.This OPD demonstrated decent indoor PV performance with a power conversion efficiency(PCE)of(11.6±0.5)%under a light emitting diode(LED)lamp with a luminance of 1000 lx.As a photodetector,this device exhibited a decent photoresponsivity of 0.15 A/W(green light)with an excellent linear dynamic range(LDR)of over 127 dB within the optical power range of 3.74×10^(−7) to 9.6×10^(−2) W/cm^(2).Furthermore,fast photoswitching behaviors could be observed with the rising/falling times of 14.5/10.4μs and a cutoff(3 dB)frequency of 37 kHz.These results might pave the way for further development of organic optoelectronic applications.