AMOLED Pixel Simulation

tftex22.in : AMOLED Pixel Simulation

Requires: VictoryProcess/Atlas-MixedMode

Minimum Versions: VictoryProcess: 7.22.1.R/Atlas 5.22.1.R
In this example, we made a simple pixel circuit which is driven by two transistor and one capacitor. The OLED(organic Emitting Diode) is directly connected to Vdd and drain side of driver n-TFT transistor so that data voltage(Vdata at node#1) is proportional to Vgs of driver TFT(Vdata = Vgs). The OLED structure is made by Atlas and a-Si(bottom gate back channel etch TFT) TFT is constructed by Victoryprocess simulator. User can make a circuit( netlist) by MixedMode syntax which is the same as spice netlist. Finally, MixedMode simulate the OLED pixel current by applying data voltage with fixed "select" voltage. In this study, we plotted the data voltage with vselect=15 V. User can change selection voltage 10V or 5V to compare the published data [1].

Referece: [1] "A novel TFT-OLED integration for OLED-independent pixel programming in amorphous-Si AMOLED pixels", Bahman Hekmatshoar et al., Journal of the SID 16/1. 2008"


Victoryprocess - a-Si:H TFT Structure This part constructs a-Si:H TFT structure with back channel etch process using victoryprocess simulator and saves "atft.str" structure for latter use in mixedmode circuit simulation.

Atlas - Organic Light Emitting Diode(OLED) Structure This part make a mesh structure for 2 layer OLED. It consists of TPD for hole transport layer and Alq3 for electron transport layer as well as light emitting material. Anode part is connected to "Vdd" and cathode is contaced with "drain" side of driver TFT.

Mixedmode The pixel circuit is described in between .BEGIN and .END. The mesh structure is loaded into Mixedmode by infile="*" in "Axxx" statement. .option select numerical solver in circuit mode and .log saves simulated curve data. .dc lin solve the circuit when data node is ramped up to 15 V. Each device is defined as device=aoled and device=atft1/atft2 to assign different physical model. Atlas/MixedMode solve simultaneously terminal current/voltage in numerical device as well as circuit nodal voltage/current in circuit part.

To load and run this example, select the Load example button in DeckBuild. This will copy the input file and any support files to your current working directory. Select the run button to execute the example.