A simple method for the photometric characterization of organic light-emitting diodes (OLEDs) is reported. It is based on the indirect measurement of the total emitted optical power by using a calibrated photodiode and the optical emission spectrum and space emission diagram of the OLED. From this and by measuring the current–voltage characteristic of the OLED all the relevant radiometric and photometric quantities can be extracted, including the external quantum efficiency. The usual method to collect all photons emitted by a LED source in the half space uses an integrating sphere with the LED source placed at the entrance hole and a photodiode (PD) placed at an exit hole at some point on the sphere surface. Here we show that the same result can be also achieved in free space by a simple geometrical arrangement of the PD in respect of the OLED source, with no need of an integrating sphere. Moreover, we find that a large area photodiode placed in contact with the OLED surface measure about 82% of the total emitted power.

报告了一种用于有机发光二极管 (OLED) 光度表征的简单方法。它基于通过使用校准的光电二极管和 OLED 的光发射光谱和空间发射图间接测量总发射光功率。由此并通过测量 OLED 的电流-电压特性，可以提取所有相关的辐射和光度量，包括外部量子效率。在半空间中收集由 LED 光源发射的所有光子的常用方法是使用积分球，其中 LED 光源放置在入口孔处，光电二极管 (PD) 放置在球体表面上某个点的出口孔处。在这里，我们表明，通过 PD 相对于 OLED 源的简单几何排列，也可以在自由空间中实现相同的结果，而无需积分球。此外，我们发现与 OLED 表面接触的大面积光电二极管约占总发射功率的 82%。